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NCI Dictionary of Cancer Terms

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NCI Dictionary of Cancer Terms


311 results found for:       H



H-ras gene    listen   (… jeen)
A gene that may cause cancer when it is mutated (changed). The H-ras gene makes the HRAS protein, which is involved in cell signaling pathways, cell growth, and apoptosis (cell death). Agents that block the actions of the mutated H-ras gene or its protein in cancer cells may stop the growth of cancer. Also called Hras gene.

H. pylori    listen   (… py-LOR-ee)
A type of bacterium that causes inflammation and ulcers in the stomach or small intestine. People with H. pylori infections may be more likely to develop cancer in the stomach, including MALT (mucosa-associated lymphoid tissue) lymphoma. Also called Helicobacter pylori.

hA20      
A substance being studied in the treatment of several types of lymphoma. It binds to the protein CD20, which is found on B cells (a type of immune system cell) and some types of lymphoma cells. This causes the immune system to kill the cancer cells. hA20 is a type of monoclonal antibody. Also called HCD20, IMMU-106, and veltuzumab.

HAART    listen  
Treatment for human immunodeficiency virus (HIV) infection that uses a combination of several antiretroviral drugs. The drugs inhibit the ability of the virus to multiply in the body, and they slow down the development of AIDS. Also called highly active antiretroviral therapy.

hair follicle    listen   (… FAH-lih-kul)
A shaft or opening on the surface of the skin through which hair grows.

hairy cell leukemia    listen   (HAYR-ee sel loo-KEE-mee-uh)
A rare type of leukemia in which abnormal B-lymphocytes (a type of white blood cell) are present in the bone marrow, spleen, and peripheral blood. When viewed under a microscope, these cells appear to be covered with tiny hair-like projections.

Halaven    listen   (HA-lih-ven)
A drug used to treat metastatic breast cancer in patients who have already been treated with other chemotherapy. It is also being studied in the treatment of other types of cancer. Halaven may block cancer cell growth by stopping cell division. It belongs to the family of drugs called antitubulin agents. Also called E7389 and eribulin mesylate.

Haldol    listen   (HAL-dol)
A drug used to treat certain mental and neurological disorders. It is also being studied in the treatment of nausea and vomiting caused by some cancer treatments. It is a type of antiemetic and a type of antipsychotic. Also called haloperidol.

half-sibling    listen   (haf-SIB-ling)
A person’s brother or sister who has one parent in common.

hallucination    listen   (huh-LOO-sih-NAY-shun)
A sight, sound, smell, taste, or touch that a person believes to be real but is not real. Hallucinations can be caused by nervous system disease, certain drugs, or mental disorders.

halofuginone hydrobromide    listen   (HA-loh-FYOO-jih-none HY-droh-BROH-mide)
A substance that is being studied for its ability to slow the growth of connective tissue and to prevent the growth of new blood vessels that tumors need to grow. It is a type of quinazolinone alkaloid and a type of antiangiogenesis agent.

haloperidol    listen   (ha-loh-PAYR-ih-dol)
A drug used to treat certain mental and neurological disorders. It is also being studied in the treatment of nausea and vomiting caused by some cancer treatments. It is a type of antiemetic and a type of antipsychotic. Also called Haldol.

Halsted radical mastectomy    listen   (HAWL-sted RA-dih-kul ma-STEK-toh-mee)
Surgery for breast cancer in which the breast, chest muscles, and all of the lymph nodes under the arm are removed. For many years, this was the breast cancer operation used most often, but it is used rarely now. Doctors consider radical mastectomy only when the tumor has spread to the chest muscles. Also called radical mastectomy.

hamartoma    listen   (HA-mar-TOH-muh)
A benign (not cancer) growth made up of an abnormal mixture of cells and tissues normally found in the area of the body where the growth occurs.

hand-foot syndrome    listen   (... SIN-drome)
A condition marked by pain, swelling, numbness, tingling, or redness of the hands or feet. It sometimes occurs as a side effect of certain anticancer drugs. Also called palmar-plantar erythrodysesthesia.

happy major    listen   (HA-pee MAY-jer)
A plant whose seeds and root have been used in some cultures to treat certain medical problems. It may have antioxidant effects. The scientific name is Arctium lappa. Also called burdock and lappa.

hard palate    listen   (... PAL-et)
The front, bony part of the roof of the mouth.

Hashimoto disease    listen   (HAH-shee-MOH-toh dih-ZEEZ)
An autoimmune condition of the thyroid gland (a gland located beneath the larynx). It is caused by the formation of antibodies that attack the thyroid gland and it usually causes hypothyroidism (too little thyroid hormone). Symptoms include fatigue, weight gain, constipation, dry skin, depression, and the inability to exercise. It is more common in females and can run in families. Also called autoimmune thyroiditis and Hashimoto thyroiditis.

Hashimoto thyroiditis    listen   (HAH-shee-MOH-toh thy-roy-DY-tis)
An autoimmune condition of the thyroid gland (a gland located beneath the larynx). It is caused by the formation of antibodies that attack the thyroid gland and it usually causes hypothyroidism (too little thyroid hormone). Symptoms include fatigue, weight gain, constipation, dry skin, depression, and the inability to exercise. It is more common in females and can run in families. Also called autoimmune thyroiditis and Hashimoto disease.

hawthorn fruit    listen   (HAW-thorn froot)
The fruit of the hawthorn tree or bush. It has been used in some cultures to treat certain medical problems, including heart problems and gastrointestinal problems.

hazard ratio    listen   (HA-zurd RAY-shee-oh)
A measure of how often a particular event happens in one group compared to how often it happens in another group, over time. In cancer research, hazard ratios are often used in clinical trials to measure survival at any point in time in a group of patients who have been given a specific treatment compared to a control group given another treatment or a placebo. A hazard ratio of one means that there is no difference in survival between the two groups. A hazard ratio of greater than one or less than one means that survival was better in one of the groups.

HBOC syndrome    listen   (… SIN-drome)
An inherited disorder in which the risk of breast cancer (especially before the age of 50) and ovarian cancer is higher than normal. Most cases of HBOC syndrome are caused by certain mutations (changes) in the BRCA1 or the BRCA2 gene. People with HBOC syndrome may also have an increased risk of other types of cancer, including pancreatic cancer, prostate cancer, and melanoma. Also called hereditary breast and ovarian cancer syndrome.

HBV      
A virus that causes hepatitis (inflammation of the liver). It is carried and passed to others through the blood and other body fluids. Different ways the virus is spread include sharing needles with an infected person and being stuck accidentally by a needle contaminated with the virus. Infants born to infected mothers may also become infected with the virus. Although many patients who are infected with HBV may not have symptoms, long-term infection may lead to cirrhosis (scarring of the liver) and liver cancer. Also called hepatitis B virus.

HCA      
A chemical that is formed when meat, poultry, or fish is cooked at high temperatures, such as frying, broiling, and barbecuing. HCAs are carcinogens (substances that may cause cancer). Also called heterocyclic amine.

HCD20      
A substance being studied in the treatment of several types of lymphoma. It binds to the protein CD20, which is found on B cells (a type of immune system cell) and some types of lymphoma cells. This causes the immune system to kill the cancer cells. HCD20 is a type of monoclonal antibody. Also called hA20, IMMU-106, and veltuzumab.

HCP      
Healthcare proxy. A type of advance directive that gives a person (such as a relative, lawyer, or friend) the authority to make healthcare decisions for another person. It becomes active when that person loses the ability to make decisions for himself or herself. Also called healthcare proxy.

hCRF      
A substance being studied in the treatment of brain cancer. It is made naturally by the hypothalamus (a part of the brain) and can also be made in the laboratory. hCRF may help reduce symptoms caused by edema (swelling) of the brain. It is a type of neurohormone. Also called human corticotropin-releasing factor.

HCT      
The amount of whole blood that is made up of red blood cells. It depends on the number and size of red blood cells. A HCT test is usually part of a complete blood count (CBC). It may be used to check for conditions such as anemia, dehydration, malnutrition, and leukemia. Also called hematocrit.

HCV      
A virus that causes hepatitis (inflammation of the liver). It is carried and passed to others through the blood and other body fluids. Different ways the virus is spread include sharing needles with an infected person and being stuck accidentally by a needle contaminated with the virus. Infants born to infected mothers may also become infected with the virus. Although patients who are infected with HCV may not have symptoms, long-term infection may lead to cirrhosis (scarring of the liver) and liver cancer. These patients may also have an increased risk for certain types of non-Hodgkin lymphoma. Also called hepatitis C virus.

HDAC      
An enzyme that removes a small molecule called an acetyl group from histones (proteins found in chromosomes). This changes the way the histones bind to DNA and may affect its activity. HDAC inhibitors are being studied in the treatment of cancer. Also called histone deacetylase.

HDAC inhibitor    listen   (...in-HIH-bih-ter)
A substance that causes a chemical change that stops tumor cells from dividing. HDAC inhibitors are being studied in the treatment of cancer. Also called histone deacetylase inhibitor.

HDAC inhibitor SNDX-275    listen   (... in-HIH-bih-ter ...)
A substance being studied in the treatment of several types of cancer. It blocks enzymes needed for cell division and may kill cancer cells. It is a type of histone deacetylase (HDAC) inhibitor. Also called entinostat and SNDX-275.

HDR      
An amount of radiation that is greater than that given in typical radiation therapy. HDR is precisely directed at the tumor to avoid damaging healthy tissue, and may kill more cancer cells in fewer treatments. Also called high-dose radiation.

HE4      
A protein found on cells that line the lungs and reproductive organs, such as the ovaries. HE4 may be found in higher than normal amounts in patients with some types of cancer, including ovarian epithelial cancer. Measuring the amount of HE4 in the blood may help plan cancer treatment or find out if cancer is getting worse or has come back. It is a type of tumor marker. Also called human epididymis protein 4.

head and neck cancer    listen   (... KAN-ser)
Cancer that arises in the head or neck region (in the nasal cavity, sinuses, lips, mouth, salivary glands, throat, or larynx [voice box]).

healing touch    listen   (HEEL-ing tuch)
A form of complementary and alternative medicine based on the belief that vital energy flows through the human body. This energy is said to be balanced or made stronger by practitioners who pass their hands over, or gently touch, a patient's body. Healing touch is being studied in patients receiving cancer therapy, to find out if it can improve quality of life, boost the immune system, or reduce side effects. Healing touch is a type of energy therapy. Also called therapeutic touch.

Health Insurance Portability and Accountability Act    listen   (helth in-SHOOR-ents por-tuh-BIH-lih-tee ... uh-KOWN-tuh-BIH-lih-tee ...)
A 1996 U.S. law that allows workers and their families to keep their health insurance when they change or lose their jobs. The law also includes standards for setting up secure electronic health records and to protect the privacy of a person’s health information and to keep it from being misused. Also called HIPAA and Kassebaum Kennedy Act.

healthcare provider    listen   (HELTH-kayr proh-VY-der)
A licensed person or organization that provides healthcare services.

healthcare proxy    listen   (HELTH-kayr PRAK-see)
A type of advance directive that gives a person (such as a relative, lawyer, or friend) the authority to make healthcare decisions for another person. It becomes active when that person loses the ability to make decisions for himself or herself. Also called HCP.

healthy control    listen   (HEL-thee kun-TROLE)
In a clinical study, a person who does not have the disorder or disease being studied. Results from healthy controls are compared to results from the group being studied.

heart cancer    listen   (hart KAN-ser)
A rare cancer that develops in tissues of the heart. Also called cardiac sarcoma.

heart disease    listen   (hart dih-ZEEZ)
A type of disease that affects the heart or blood vessels. The risk of certain heart diseases may be increased by smoking, high blood pressure, high cholesterol, unhealthy diet, lack of exercise, and obesity. The most common heart disease is coronary artery disease (narrow or blocked coronary arteries), which can lead to chest pain, heart attacks, or stroke. Other heart diseases include congestive heart failure, heart rhythm problems, congenital heart disease (heart disease at birth), and endocarditis (inflamed inner layer of the heart). Also called cardiovascular disease.

heart rate    listen   (hart rayt)
In medicine, the number of times the heart beats within a certain time period, usually a minute. The heart rate can be felt at the wrist, side of the neck, back of the knees, top of the foot, groin, and other places in the body where an artery is close to the skin. The resting heart rate is normally between 60 and 100 beats a minute in a healthy adult who is at rest. Measuring the heart rate gives important information about a person’s health. Also called pulse.

heat-shock protein    listen   (... PROH-teen)
One of a group of proteins that help protect cells from stresses such as heat, cold, and low amounts of oxygen or glucose (sugar). Heat-shock proteins help other proteins function in normal cells and may be present at high levels in cancer cells. Blocking the activity of a heat-shock protein called HSP90 is being studied in the treatment of cancer. Other heat-shock proteins including HSP70 and gp96 are being studied in vaccines to treat cancer. Also called HSP and stress protein.

Hedyotis diffusa    listen   (heh-dee-OH-tis dih-FYOO-suh)
An herb used in traditional Chinese medicine to treat certain medical problems. It has been used to boost the immune system and may have anticancer effects.

helical computed tomography    listen   (HEE-lih-kul kum-PYOO-ted toh-MAH-gruh-fee)
A procedure that uses a computer linked to an x-ray machine to make a series of detailed pictures of areas inside the body. The x-ray machine scans the body in a spiral path. This allows more images to be made in a shorter time than with older CT methods. A dye may be injected into a vein or swallowed to help the organs or tissues show up more clearly on the x-ray. Helical computed tomography also creates more detailed pictures and may be better at finding small abnormal areas inside the body. It may be used to help diagnose disease, plan treatment, or find out how well treatment is working. Also called spiral CT scan.

helical tomotherapy    listen   (HEE-lih-kul toh-mah-THAYR-uh-pee)
A type of therapy in which radiation is aimed at a tumor from many different directions. The patient lays on a table and is moved through a donut-shaped machine. The radiation source in the machine rotates around the patient in a spiral pattern. Before radiation, a 3-dimensional (3-D) image of the tumor is taken. This helps doctors find the highest dose of radiation that can be used to kill tumor cells while causing less damage to nearby tissue. Helical tomotherapy is a type of intensity-modulated radiation therapy (IMRT). Also called tomotherapy.

Helicobacter pylori    listen   (HEEL-ih-koh-BAK-ter py-LOR-ee)
A type of bacterium that causes inflammation and ulcers in the stomach or small intestine. People with Helicobacter pylori infections may be more likely to develop cancer in the stomach, including MALT (mucosa-associated lymphoid tissue) lymphoma. Also called H. pylori.

helper T cell    listen   (HEL-per … sel)
A type of immune cell that stimulates killer T cells, macrophages, and B cells to make immune responses. A helper T cell is a type of white blood cell and a type of lymphocyte. Also called CD4-positive T lymphocyte.

hemagglutinin-neuraminidase    listen   (HEE-muh-GLOO-tih-nin-NOOR-uh-MIH-nih-days)
A protein found in the outer coat of paramyxoviruses. This protein helps virus particles bind to cells, making infection easier.

hemangiopericytoma    listen   (hee-MAN-jee-oh-PAYR-ih-sy-TOH-muh)
A type of cancer involving blood vessels and soft tissue.

hemangiosarcoma    listen   (hee-MAN-jee-oh-sar-KOH-muh)
A type of cancer that begins in the cells that line blood vessels.

hematocrit    listen   (hee-MA-toh-krit)
The amount of whole blood that is made up of red blood cells. It depends on the number and size of red blood cells. A hematocrit test is usually part of a complete blood count (CBC). It may be used to check for conditions such as anemia, dehydration, malnutrition, and leukemia. Also called HCT.

hematogenous    listen   (HEE-muh-TAH-jeh-nus)
Originating in the blood or spread through the bloodstream.

hematologic cancer    listen   (HEE-muh-tuh-LAH-jik KAN-ser)
Cancer that begins in blood-forming tissue, such as the bone marrow, or in the cells of the immune system. Examples of hematologic cancer are leukemia, lymphoma, and multiple myeloma. Also called blood cancer.

hematologist    listen   (HEE-muh-TAH-loh-jist)
A doctor who specializes in treating blood disorders.

hematoma    listen   (HEE-muh-TOH-muh)
A pool of clotted or partially clotted blood in an organ, tissue, or body space, usually caused by a broken blood vessel.

hematopathology laboratory    listen   (hee-MA-toh-pa-THAH-loh-jee LA-bruh-tor-ee)
A laboratory that specializes in doing tests that help to diagnose and treat diseases of the blood, bone marrow, and lymph system.

hematopoiesis    listen   (hee-MA-toh-poy-EE-sis)
The formation of new blood cells.

hematopoietic growth factor    listen   (hee-MA-toh-poy-EH-tik ...)
A group of proteins that causes blood cells to grow and mature.

hematopoietic stem cell    listen   (hee-MA-toh-poy-EH-tik stem sel)
An immature cell that can develop into all types of blood cells, including white blood cells, red blood cells, and platelets. Hematopoietic stem cells are found in the peripheral blood and the bone marrow.

hematopoietic tissue    listen   (hee-MA-toh-poy-EH-tik TIH-shoo)
Tissue in which new blood cells are formed.

hematoporphyrin derivative    listen   (HEE-muh-toh-POR-fih-rin deh-RIH-vuh-tiv)
A drug used in photodynamic therapy that is absorbed by tumor cells. When exposed to light, it becomes active and kills the cancer cells.

hematuria    listen   (HEE-muh-TOOR-ee-uh)
Blood in the urine.

heme    listen   (heem)
The part of certain molecules that contains iron. The heme part of hemoglobin is the substance inside red blood cells that binds to oxygen in the lungs and carries it to the tissues.

hemihypertrophy    listen   (HEH-mee-hy-PER-troh-fee)
A condition in which one side of the body or a part of one side is larger than the other. Children with hemihypertrophy have an increased risk of developing certain types of cancer, including Wilms tumor (a childhood kidney cancer) and liver cancer.

hemilaryngectomy    listen   (HEM-ee-LAYR-in-JEK-toh-mee)
An operation to remove one side of the larynx (voicebox).

hemochromatosis    listen   (HEE-moh-kroh-muh-TOH-sis)
A condition in which the body takes up and stores more iron than it needs. The extra iron is stored in the liver, heart, and pancreas, which may cause liver disease, heart problems, organ failure, and cancer. It may also cause bronze skin, diabetes, pain in the joints and abdomen, tiredness, and impotence. Hemochromatosis may be inherited, or it may be caused by blood transfusions. Also called iron overload.

hemoglobin    listen   (HEE-moh-GLOH-bin)
A protein inside red blood cells that carries oxygen from the lungs to tissues and organs in the body and carries carbon dioxide back to the lungs. Testing for the amount of hemoglobin in the blood is usually part of a complete blood cell (CBC) test. It is used to check for conditions such as anemia, dehydration, and malnutrition.

hemolysis    listen   (hee-MAH-lih-sis)
The breakdown of red blood cells. Some diseases, medicines, and toxins may cause red blood cells to break down more quickly than usual.

hemophagocytic lymphohistiocytosis    listen   (HEE-moh-FA-goh-SIH-tik LIM-foh-HIS-tee-oh-sy-TOH-sis)
A rare disorder in which histiocytes and lymphocytes (types of white blood cells) build up in organs including the skin, spleen, and liver, and destroy other blood cells. Hemophagocytic lymphohistiocytosis may be inherited or caused by certain conditions or diseases, including infections, immunodeficiency (inability of the body to fight infections), and cancer. Also called HLH.

hemophilia    listen   (HEE-moh-FIH-lee-uh)
Group of hereditary disorders in which affected individuals fail to make enough of certain proteins needed to form blood clots.

hemoptysis    listen   (hee-MOP-tih-sis)
Coughing or spitting up blood from the respiratory tract.

hemorrhage    listen   (HEH-muh-rij)
In medicine, loss of blood from damaged blood vessels. A hemorrhage may be internal or external, and usually involves a lot of bleeding in a short time.

hemorrhagic cystitis    listen   (HEH-muh-RA-jik sis-TY-tis)
A condition in which the lining of the bladder becomes inflamed and starts to bleed. The blood can be seen in the urine. Symptoms include pain and a burning feeling while urinating, feeling a need to urinate often, and being unable to control the flow of urine. Hemorrhagic cystitis may be caused by anticancer drugs, radiation therapy, infection, or being exposed to chemicals, such as dyes or insecticides.

hemorrhoid    listen   (HEH-muh-ROYD)
An enlarged or swollen blood vessel, usually located near the anus or the rectum.

heparin    listen   (HEH-puh-rin)
A substance that slows the formation of blood clots. Heparin is made by the liver, lungs, and other tissues in the body and can also made in the laboratory. Heparin may be injected into muscle or blood to prevent or break up blood clots. It is a type of anticoagulant.

hepatectomy    listen   (HEH-puh-TEK-toh-mee)
Surgery to remove all or part of the liver.

hepatic    listen   (heh-PA-tik)
Refers to the liver.

hepatic arterial infusion    listen   (heh-PA-tik ar-TEER-ee-ul in-FYOO-zhun)
A procedure to deliver chemotherapy directly to the liver. Catheters are put into an artery in the groin that leads directly to the liver, and drugs are given through the catheters.

hepatic arterial occlusion    listen   (heh-PA-tik ar-TEER-ee-ul uh-KLOO-zhun)
A block in blood flow to the liver. It can happen while giving chemotherapy through a catheter in the hepatic artery. Sometimes doctors use drugs or other agents to cause hepatic arterial occlusion on purpose. This block of blood flow to the liver helps kill cancer cells growing in the liver.

hepatic artery    listen   (heh-PA-tik AR-tuh-ree)
The major blood vessel that carries blood to the liver.

hepatic portal vein    listen   (heh-PA-tik POR-tul vayn)
A blood vessel that carries blood to the liver from the intestines, spleen, pancreas, and gallbladder. Also called portal vein.

hepatic veno-occlusive disease    listen   (heh-PA-tik VEE-noh-uh-KLOO-siv dih-ZEEZ)
A condition in which some of the veins in the liver are blocked. This causes a decrease in blood flow inside the liver and may lead to liver damage. Signs and symptoms include weight gain, yellowing of the skin and whites of the eyes, dark-colored urine, and increased liver size. It may occur at some point in time after radiation therapy to the liver and bile ducts or after high-dose anticancer drugs were given before a stem cell transplant. Also called sinusoidal obstruction syndrome.

hepatitis    listen   (HEH-puh-TY-tis)
Disease of the liver causing inflammation. Symptoms include an enlarged liver, fever, nausea, vomiting, abdominal pain, and dark urine.

hepatitis A vaccine    listen   (HEH-puh-TY-tis ... vak-SEEN)
A vaccine used to prevent infection with the hepatitis A virus, which causes a serious liver disease. The vaccine is made of a weakened form of the virus that cannot cause disease but causes the body’s immune system to make antibodies that destroy the hepatitis A virus.

hepatitis A virus    listen   (HEH-puh-TY-tis ... VY-rus)
A virus that causes a serious liver disease. It is usually spread by contact with an infected person’s stool by eating food he or she has handled after not washing hands, but it can be spread in other ways. Symptoms of infection include jaundice, dark urine, and fever and other flu-like symptoms.

hepatitis B virus    listen   (HEH-puh-TY-tis ... VY-rus)
A virus that causes hepatitis (inflammation of the liver). It is carried and passed to others through the blood and other body fluids. Different ways the virus is spread include sharing needles with an infected person and being stuck accidentally by a needle contaminated with the virus. Infants born to infected mothers may also become infected with the virus. Although many patients who are infected with hepatitis B virus may not have symptoms, long-term infection may lead to cirrhosis (scarring of the liver) and liver cancer. Also called HBV.

hepatitis C virus    listen   (HEH-puh-TY-tis ... VY-rus)
A virus that causes hepatitis (inflammation of the liver). It is carried and passed to others through the blood and other body fluids. Different ways the virus is spread include sharing needles with an infected person and being stuck accidentally by a needle contaminated with the virus. Infants born to infected mothers may also become infected with the virus. Although patients who are infected with hepatitis C virus may not have symptoms, long-term infection may lead to cirrhosis (scarring of the liver) and liver cancer. These patients may also have an increased risk for certain types of non-Hodgkin lymphoma. Also called HCV.

hepatitis D virus    listen   (HEH-puh-TY-tis … VY-rus)
A type of hepatitis virus that may be present in the body at the same time as the hepatitis B virus. It makes the hepatitis (inflammation of the liver) caused by hepatitis B much worse. The hepatitis D virus and the hepatitis B virus are spread to others through blood or sexual contact. Infants born to infected mothers may also become infected with the virus. Also called hepatitis delta virus.

hepatitis delta virus    listen   (HEH-puh-TY-tis DEL-tuh VY-rus)
A type of hepatitis virus that may be present in the body at the same time as the hepatitis B virus. It makes the hepatitis (inflammation of the liver) caused by hepatitis B much worse. The hepatitis delta virus and the hepatitis B virus are spread to others through blood or sexual contact. Infants born to infected mothers may also become infected with the virus. Also called hepatitis D virus.

hepatitis E virus    listen   (HEH-puh-TY-tis … VY-rus)
A virus that causes hepatitis (inflammation of the liver). It is usually spread through food that has been handled by an infected person, or through drinking water that is contaminated with human waste.

hepatitis G virus    listen   (HEH-puh-TY-tis … VY-rus)
A virus that may be found in patients with hepatitis (inflammation of the liver). It is spread to others through blood or sexual contact. Infants born to infected mothers may also become infected with the virus.

hepatobiliary    listen   (heh-PA-toh-BIH-lee-AYR-ee)
Having to do with the liver, bile ducts, and/or gallbladder.

hepatoblastoma    listen   (HEH-puh-toh-bla-STOH-muh)
A type of liver tumor that occurs in infants and children.

hepatocellular carcinoma    listen   (heh-PA-toh-SEL-yoo-ler KAR-sih-NOH-muh)
A type of adenocarcinoma and the most common type of liver tumor.

hepatocyte    listen   (heh-PA-toh-site)
A liver cell.

hepatoma    listen   (HEH-puh-TOH-muh)
A liver tumor.

hepatomegaly    listen   (HEH-puh-toh-MEH-guh-lee)
Enlarged liver.

HER1    listen  
The protein found on the surface of some cells and to which epidermal growth factor binds, causing the cells to divide. It is found at abnormally high levels on the surface of many types of cancer cells, so these cells may divide excessively in the presence of epidermal growth factor. Also called EGFR, epidermal growth factor receptor, and ErbB1.

HER2 positive    listen   (… PAH-zih-tiv)
Describes cancer cells that have too much of a protein called HER2 on their surface. In normal cells, HER2 helps to control cell growth. When it is made in larger than normal amounts by cancer cells, the cells may grow more quickly and be more likely to spread to other parts of the body. Checking to see if a cancer is HER2 positive may help plan treatment, which may include drugs that kill HER2 positive cancer cells. Cancers that may be HER2 positive include breast, bladder, pancreatic, ovarian, and stomach cancers. Also called c-erbB-2 positive and human epidermal growth factor receptor 2 positive.

HER2/neu    listen  
A protein involved in normal cell growth. It is found on some types of cancer cells, including breast and ovarian. Cancer cells removed from the body may be tested for the presence of HER2/neu to help decide the best type of treatment. HER2/neu is a type of receptor tyrosine kinase. Also called c-erbB-2, human EGF receptor 2, and human epidermal growth factor receptor 2.

herba Scutellaria barbatae    listen   (ER-buh skoo-teh-LAYR-ee-uh BAR-buh-tay)
An herb used in traditional Chinese medicine to treat certain medical problems. It may have anticancer effects.

herbal    listen   (ER-bul)
Having to do with plants.

herbal cigarette    listen   (ER-bul SIH-guh-ret)
A type of cigarette that contains a mixture of flowers, herbs, and other natural ingredients. Herbal cigarettes do not contain tobacco or nicotine. When they are smoked, they make many of the same harmful chemicals found in tobacco smoke, including tar and carbon monoxide.

herbal medicine    listen   (ER-bul MEH-dih-sin)
A type of medicine that uses roots, stems, leaves, flowers, or seeds of plants to improve health, prevent disease, and treat illness.

herbal supplement    listen   (ER-bul SUH-pleh-ment)
A product made from a plant that is thought to be useful in treating disease or staying healthy. Herbal supplements are taken by mouth.

herbicide    listen   (ER-bih-side)
A chemical that kills plants.

Herceptin    listen   (her-SEP-tin)
A drug used to treat breast cancer that is HER2-positive (expresses the human epidermal growth factor receptor 2). It is also used with other drugs to treat HER2-positive stomach cancer that has not already been treated and has spread to other parts of the body. It is being studied in the treatment of other types of cancer. Herceptin binds to HER2 on the surface of HER2-positive cancer cells, and may kill them. It is a type of monoclonal antibody. Also called trastuzumab.

hereditary    listen   (heh-REH-dih-tayr-ee)
In medicine, describes the passing of genetic information from parent to child through the genes in sperm and egg cells. Also called inherited.

hereditary breast and ovarian cancer syndrome    listen   (heh-REH-dih-tayr-ee brest … oh-VAYR-ee-un KAN-ser SIN-drome)
An inherited disorder in which the risk of breast cancer (especially before the age of 50) and ovarian cancer is higher than normal. Most cases of hereditary breast and ovarian cancer syndrome are caused by certain mutations (changes) in the BRCA1 or the BRCA2 gene. People with hereditary breast and ovarian cancer syndrome may also have an increased risk of other types of cancer, including pancreatic cancer, prostate cancer, and melanoma. Also called HBOC syndrome.

hereditary cancer syndrome    listen   (heh-REH-dih-tayr-ee KAN-ser SIN-drome)
A type of inherited disorder in which there is a higher-than-normal risk of certain types of cancer. Hereditary cancer syndromes are caused by mutations (changes) in certain genes passed from parents to children. In a hereditary cancer syndrome, certain patterns of cancer may be seen within families. These patterns include having several close family members (such as a mother, daughter, and sister) with the same type of cancer, developing cancer at an early age, or having two or more types of cancer develop in the same person. Examples of hereditary cancer syndromes are hereditary breast and ovarian cancer syndrome, Li-Fraumeni syndrome, Cowden syndrome, and Lynch syndrome. Also called inherited cancer syndrome.

hereditary leiomyomatosis and renal cell cancer syndrome    listen   (heh-REH-dih-tayr-ee LY-oh-MY-oh-muh-TOH-sis ... REE-nul sel KAN-ser SIN-drome)
A rare inherited disorder that increases the risk of developing benign (not cancer) tumors of the skin and the uterus (leiomyomas) and malignant (cancer) tumors of the uterus (leiomyosarcoma) and the kidney. Also called HLRCC.

hereditary mutation    listen   (heh-REH-dih-tayr-ee myoo-TAY-shun)
A gene change in a body's reproductive cell (egg or sperm) that becomes incorporated into the DNA of every cell in the body of the offspring. Hereditary mutations are passed on from parents to offspring. Also called germline mutation.

hereditary nonpolyposis colon cancer    listen   (heh-REH-dih-tayr-ee non-PAH-lee-POH-sis KOH-lun KAN-ser)
An inherited disorder in which affected individuals have a higher-than-normal chance of developing colorectal cancer and certain other types of cancer, often before the age of 50. Also called HNPCC and Lynch syndrome.

hereditary paraganglioma-pheochromocytoma syndrome    listen   (heh-REH-dih-tayr-ee PAYR-uh-GANG-glee-OH-muh-FEE-oh-KROH-moh-sy-TOH-muh SIN-drome)
A rare, genetic disorder marked by tumors called paragangliomas, which are found in paraganglia. Paraganglia are groups of nerve-like cells found near the adrenal glands and near blood vessels or nerves in the head, neck, chest, abdomen, and pelvis. Paragangliomas that form in the adrenal glands are called pheochromocytomas. Paragangliomas are usually benign (not cancer), but sometimes become malignant (cancerous). People with hereditary paraganglioma-pheochromocytoma syndrome usually have more than one paraganglioma, and may have an increased risk of certain types of cancer, such as kidney cancer and thyroid cancer.

heritage    listen   (HAYR-ih-tij)
Something handed down from the past, such as a tradition, birthright, or inherited traits.

hernia    listen   (HER-nee-uh)
The bulging of an internal organ through a weak area or tear in the muscle or other tissue that holds it in place. Most hernias occur in the abdomen.

heroin    listen   (HAYR-oh-win)
A substance made from morphine. Heroin is very addictive and it is illegal to use or sell it in the United States. It is a type of opiate.

herpes simplex virus    listen   (HER-peez SIM-plex VY-rus)
A type of virus that causes herpes infections and has DNA as its genetic material. There are two types of herpes simplex viruses. Infections with type 1 viruses cause cold sores on the lips or nostrils. Infections with type 2 viruses cause sores on the genitals (external and internal sex organs and glands). Also called HHV, HSV, and human herpesvirus.

herpesvirus    listen   (HER-peez-VY-rus)
A member of the herpes family of viruses.

heterocyclic amine    listen   (HEH-teh-roh-SY-klik A-meen)
A chemical that is formed when meat, poultry, or fish is cooked at high temperatures, such as frying, broiling, and barbecuing. Heterocyclic amines are carcinogens (substances that may cause cancer). Also called HCA.

heterogeneous    listen   (HEH-teh-roh-JEE-nee-us)
Made up of elements or ingredients that are not alike.

heterogenic    listen   (HEH-teh-roh-JEH-nik)
Derived from a different source or species. Also called heterogenous.

heterogenous    listen   (HEH-teh-RAH-jeh-nus)
Derived from a different source or species. Also called heterogenic.

hexyl 5-aminolevulinate    listen   (HEK-sul 5-uh-MEE-noh-LEH-vyoo-LIH-nayt)
A substance that is used to find and kill tumor cells. It enters tumor cells and becomes activated when exposed to a special type of light. A chemical reaction causes the cells to produce fluorescent light and die.

HGS-ETR1      
A substance being studied in the treatment of some types of cancer. It binds to a protein called TRAIL R1 on the surface of some tumor cells. This may kill the tumor cells. HGS-ETR1 is a type of monoclonal antibody. Also called anti-TRAIL R1-mAb and mapatumumab.

HGS-ETR2      
A substance being studied in the treatment of some types of cancer. It binds to a protein called TRAIL-R2 on the surface of some tumor cells, which may kill the tumor cells. HGS-ETR2 is a type of monoclonal antibody. Also called anti-TRAIL R2 mAb HGS-ETR2 and lexatumumab.

HHV      
A type of virus that causes herpes infections and has DNA as its genetic material. There are two types of HHVs. Infections with type 1 viruses cause cold sores on the lips or nostrils. Infections with type 2 viruses cause sores on the genitals (external and internal sex organs and glands). Also called herpes simplex virus, HSV, and human herpesvirus.

HHV8      
A type of virus that causes Kaposi sarcoma (a rare cancer in which lesions grow in the skin, lymph nodes, lining of the mouth, nose, and throat, and other tissues of the body). HHV8 also causes certain types of lymphoma (cancer that begins in cells of the immune system). Also called human herpesvirus 8, Kaposi sarcoma-associated herpesvirus, and KSHV.

HIFU      
A procedure in which high-energy sound waves are aimed directly at an area of abnormal cells or tissue in the body. The waves create heat that kills the cells. HIFU is being studied in the treatment of prostate cancer and some other types of cancer and other diseases. Also called high-intensity focused ultrasound therapy.

high blood pressure    listen   (hy blud PREH-sher)
A blood pressure of 140/90 or higher. High blood pressure usually has no symptoms. It can harm the arteries and cause an increase in the risk of stroke, heart attack, kidney failure, and blindness. Also called hypertension.

high blood sugar    listen   (hy blud SHUH-ger)
Higher than normal amount of glucose (a type of sugar) in the blood. High blood sugar can be a sign of diabetes or other conditions. Also called hyperglycemia.

high grade    listen   (hy grayd)
A term used to describe cells and tissue that look abnormal under a microscope. High-grade cancer cells tend to grow and spread more quickly than low-grade cancer cells. Cancer grade may be used to help plan treatment and determine prognosis. High-grade cancers usually have a worse prognosis than low-grade cancers and may need treatment right away or treatment that is more aggressive (intensive).

high-dose chemotherapy    listen   (hy-dose kee-moh-THAYR-uh-pee)
An intensive drug treatment to kill cancer cells, but that also destroys the bone marrow and can cause other severe side effects. High-dose chemotherapy is usually followed by bone marrow or stem cell transplantation to rebuild the bone marrow.

high-dose radiation    listen   (hy-dose RAY-dee-AY-shun)
An amount of radiation that is greater than that given in typical radiation therapy. High-dose radiation is precisely directed at the tumor to avoid damaging healthy tissue, and may kill more cancer cells in fewer treatments. Also called HDR.

high-dose-rate remote brachytherapy    listen   (hy-dose-rayt ree-MOTE BRAY-kee-THAYR-uh-pee)
A type of internal radiation treatment in which the radioactive source is removed between treatments. Also called high-dose-rate remote radiation therapy and remote brachytherapy.

high-dose-rate remote radiation therapy    listen   (hy-dose-rayt ree-MOTE RAY-dee-AY-shun THAYR-uh-pee)
A type of internal radiation treatment in which the radioactive source is removed between treatments. Also called high-dose-rate remote brachytherapy and remote brachytherapy.

high-energy photon therapy    listen   (hy-EH-ner-jee FOH-ton THAYR-uh-pee)
A type of radiation therapy that uses high-energy photons (units of light energy). High-energy photons penetrate deeply into tissues to reach tumors while giving less radiation to superficial tissues such as the skin.

high-grade lymphoma    listen   (... lim-FOH-muh)
A type of lymphoma that grows and spreads quickly and has severe symptoms. Also called aggressive lymphoma and intermediate-grade lymphoma.

high-grade squamous intraepithelial lesion    listen   (... SKWAY-mus IN-truh-eh-pih-THEE-lee-ul LEE-zhun)
Cells of the uterine cervix that are moderately or severely abnormal and may become cancer. Also called HSIL.

high-intensity focused ultrasound therapy    listen   (hy-in-TEN-sih-tee FOH-kust UL-truh-sownd THAYR-uh-pee)
A procedure in which high-energy sound waves are aimed directly at an area of abnormal cells or tissue in the body. The waves create heat that kills the cells. High-intensity focused ultrasound therapy is being studied in the treatment of prostate cancer and some other types of cancer and other diseases. Also called HIFU.

high-risk cancer    listen   (hy-risk KAN-ser)
Cancer that is likely to recur (come back), or spread.

high-risk HPV    listen   (hy-risk …)
A type of human papilloma virus (HPV) that can cause cervical cancer and other types of cancer, such as cancers of the anus, vagina, vulva, penis, and oropharynx. Most high-risk HPV infections go away on their own without treatment, and do not cause cancer. Also called high-risk human papillomavirus.

high-risk human papillomavirus    listen   (hy-risk HYOO-mun PA-pih-LOH-muh-VY-rus)
A type of human papilloma virus (HPV) that can cause cervical cancer and other types of cancer, such as cancers of the anus, vagina, vulva, penis, and oropharynx. Most high-risk human papillomavirus infections go away on their own without treatment, and do not cause cancer. Also called high-risk HPV.

high-selenium Brassica juncea    listen   (hy-seh-LEE-nee-um BRA-sih-kuh JUN-see-uh)
Brassica juncea that has been grown in high levels of selenium. Brassica juncea is a plant of the cabbage family that has been used in some cultures to treat certain medical problems, including arthritis, colds, stomach disorders, and tumors. The plant stores minerals, including selenium which may stop tumor cells from growing. High-selenium Brassica juncea is being studied in the treatment of cancer. Brassica juncea is also known as Indian mustard.

highly active antiretroviral therapy    listen   (...AN-tee-REH-troh-VY-rul THAYR-uh-pee)
Treatment for human immunodeficiency virus (HIV) infection that uses a combination of several antiretroviral drugs. The drugs inhibit the ability of the virus to multiply in the body, and they slow down the development of AIDS. Also called HAART.

hilar    listen   (HY-ler)
Refers to the area where nerves and blood vessels attach to an organ.

HIPAA    listen   (HIH-puh)
A 1996 U.S. law that allows workers and their families to keep their health insurance when they change or lose their jobs. The law also includes standards for setting up secure electronic health records and to protect the privacy of a person’s health information and to keep it from being misused. Also called Health Insurance Portability and Accountability Act and Kassebaum Kennedy Act.

Hirschsprung disease    listen   (HIRSH-sprung dih-ZEEZ)
A condition in which certain nerve cells are missing from the muscle layers of part of the large intestine. This causes severe constipation or blockage of the large intestine. Constipation is when stool becomes hard, dry, and difficult to pass and bowel movements occur less often than normal. Other symptoms include swollen abdomen, vomiting, bloody diarrhea, gas, lack of energy, and trouble gaining weight. Hirschsprung disease is present from birth, but the symptoms may not appear until later in a child’s life. This condition has been linked to an increased risk of thyroid cancer and neuroblastoma. Also called aganglionic megacolon.

histamine    listen   (HIS-tuh-meen)
A substance that has many effects in the body. It is released from some types of white blood cells during allergic reactions. It causes small blood vessels to dilate (widen) and become leaky, which can cause tissues to swell. It also causes smooth muscles to contract, gastric acid to be made, and the heart rate to increase. Histamine is used in tests for allergies, asthma, and gastric acid secretion. It is a type of neurotransmitter.

histamine dihydrochloride    listen   (HIS-tuh-meen dy-HY-droh-KLOR-ide)
A substance being studied in the treatment of some types of cancer and other conditions. When used together with interleukin-2, histamine dihydrochloride may help some immune cells find and kill tumor cells. It is a type of biological response modifier. Also called Maxamine.

histiocytic lymphoma    listen   (HIS-tee-oh-SIH-tik lim-FOH-muh)
An outdated term referring to non-Hodgkin lymphomas made up of large abnormal lymphoid cells. Histiocytic lymphomas include mature B-cell and T-cell non-Hodgkin lymphomas. Many tumors that were once called histiocytic lymphomas are now considered to be a type of large cell lymphoma.

histologic examination    listen   (HIS-tuh-LAH-jik eg-ZA-mih-NAY-shun)
The examination of tissue specimens under a microscope.

histologic grade    listen   (HIS-tuh-LAH-jik grayd)
A description of a tumor based on how abnormal the cancer cells look under a microscope and how quickly the tumor is likely to grow and spread. Low-grade cancer cells look more like normal cells and tend to grow and spread more slowly than high-grade cancer cells. Grading systems are different for each type of cancer. They are used to help plan treatment and determine prognosis. Also called tumor grade.

histology    listen   (his-TAH-loh-jee)
The study of tissues and cells under a microscope.

histone    listen   (HIS-tone)
A type of protein found in chromosomes. Histones bind to DNA, help give chromosomes their shape, and help control the activity of genes.

histone deacetylase    listen   (HIS-tone dee-uh-SEH-tih-lays)
An enzyme that removes a small molecule called an acetyl group from histones (proteins found in chromosomes). This changes the way the histones bind to DNA and may affect its activity. Histone deacetylase inhibitors are being studied in the treatment of cancer. Also called HDAC.

histone deacetylase inhibitor    listen   (HIS-tone dee-uh-SEH-tih-lays in-HIH-bih-ter)
A substance that causes a chemical change that stops tumor cells from dividing. Histone deacetylase inhibitors are being studied in the treatment of cancer. Also called HDAC inhibitor.

histopathology    listen   (HIS-toh-puh-THAH-loh-jee)
The study of diseased cells and tissues using a microscope.

historic cohort study    listen   (hih-STOR-ik KOH-hort STUH-dee)
A research study in which the medical records of groups of individuals who are alike in many ways but differ by a certain characteristic (for example, female nurses who smoke and those who do not smoke) are compared for a particular outcome (such as lung cancer). Also called retrospective cohort study.

historical control subject    listen   (hih-STOR-ih-kul kun-TROLE SUB-jekt)
An individual treated in the past and used in a comparison group when researchers analyze the results of a clinical study that had no control group. The use of a control, or comparison, group helps researchers determine the effects of a new treatment more accurately.

HIV      
The cause of acquired immunodeficiency syndrome (AIDS). Also called human immunodeficiency virus.

HIV antibody    listen   (... AN-tee-BAH-dee)
A substance produced by certain white blood cells in reaction to contact with the human immunodeficiency virus (HIV).

HIV negative    listen   (... NEH-guh-tiv)
Refers to a person who is not infected with the human immunodeficiency virus (HIV). HIV is the virus that causes acquired immunodeficiency syndrome (AIDS).

HIV positive    listen   (... PAH-zih-tiv)
Refers to a person who is infected with the human immunodeficiency virus (HIV). HIV is the virus that causes acquired immunodeficiency syndrome (AIDS).

HIV test       (… test)
A test to check for human immunodeficiency virus (HIV) infection. HIV is the virus that causes acquired immunodeficiency syndrome (AIDS). The most common type of HIV test is called the HIV antibody test, which checks for antibodies against HIV in a sample of blood, urine, or fluid from the mouth. It can take from 2 weeks to 6 months after a person is infected with HIV before the antibodies are found with an HIV antibody test. Another type of HIV test checks for RNA or DNA from HIV in a sample of blood. This test can find HIV in a person’s blood about 9-11 days after the person is infected with the virus.

HIV window period       (… WIN-doh PEER-ee-ud)
The time period that starts when a person becomes infected with the human immunodeficiency virus (HIV) and ends when the body makes enough antibodies against the virus or HIV DNA or RNA to be found with an HIV test. For the test that looks for antibodies against HIV, the HIV window period can last from 2 weeks to 6 months. For the HIV DNA or RNA test, the HIV window period is about 9-11 days. During the HIV window period, an infected person may have negative HIV test results but still be able to infect other people.

hives    listen   (hyvz)
Itchy, raised red areas on the skin. Hives are caused by a reaction to certain foods, drugs, infections, or emotional stress. Also called urticaria.

HLA      
A type of molecule found on the surface of most cells in the body. HLAs play an important part in the body's immune response to foreign substances. They make up a person’s tissue type, which varies from person to person. HLA tests are done before a donor stem cell or organ transplant, to find out if tissues match between the donor and the person receiving the transplant. Also called human leukocyte antigen and human lymphocyte antigen.

HLA matching    listen   (… MA-ching)
A process in which blood or tissue samples are tested for human leukocyte antigens (HLAs). HLAs are molecules found on the surface of most cells in the body. They make up a person’s tissue type, which varies from person to person. They play an important part in the body's immune response to foreign substances. HLA matching is done before a donor stem cell or organ transplant to find out if tissues match between the donor and the person receiving the transplant. Also called human leukocyte antigen matching.

HLH      
A rare disorder in which histiocytes and lymphocytes (types of white blood cells) build up in organs including the skin, spleen, and liver, and destroy other blood cells. HLH may be inherited or caused by certain conditions or diseases, including infections, immunodeficiency (inability of the body to fight infections), and cancer. Also called hemophagocytic lymphohistiocytosis.

hLL1      
A substance being studied in the treatment of multiple myeloma and several other types of cancer. It binds to CD74, a protein on the surface of myeloma cells and certain other types of cells. It may help kill cancer cells. hLL1 is a type of monoclonal antibody. Also called IMMU-110 and milatuzumab.

HLRCC      
A rare inherited disorder that increases the risk of developing benign (not cancer) tumors of the skin and the uterus (leiomyomas) and malignant (cancer) tumors of the uterus (leiomyosarcoma) and the kidney. Also called hereditary leiomyomatosis and renal cell cancer syndrome.

HMG-CoA reductase inhibitor    listen   (HMG-koh-A ree-DUK-tays in-HIH-bih-ter)
A substance that blocks an enzyme needed by the body to make cholesterol and lowers the amount of cholesterol in the blood. HMG-CoA reductase inhibitor drugs are called statins. Also called hydroxymethylglutaryl-coenzyme A reductase inhibitor.

HMGA1      
A protein that binds to the DNA and certain proteins in chromosomes. It is involved in many functions in the cell, and helps protect cells from dying. HMGA1 is found at high levels in several types of cancer cells.

HMR 1275      
A substance being studied in the treatment of several types of cancer. It stops cells from dividing and may kill cancer cells. It is a type of cyclin-dependent kinase (CDK) inhibitor. Also called alvocidib and flavopiridol.

HNPCC      
An inherited disorder in which affected individuals have a higher-than-normal chance of developing colorectal cancer and certain other types of cancer, often before the age of 50. Also called hereditary nonpolyposis colon cancer and Lynch syndrome.

Hodgkin disease    listen   (HOJ-kin dih-ZEEZ)
A cancer of the immune system that is marked by the presence of a type of cell called the Reed-Sternberg cell. The two major types of Hodgkin disease are classical Hodgkin lymphoma and nodular lymphocyte-predominant Hodgkin lymphoma. Symptoms include the painless enlargement of lymph nodes, spleen, or other immune tissue. Other symptoms include fever, weight loss, fatigue, or night sweats. Also called Hodgkin lymphoma.

Hodgkin lymphoma    listen   (HOJ-kin lim-FOH-muh)
A cancer of the immune system that is marked by the presence of a type of cell called the Reed-Sternberg cell. The two major types of Hodgkin lymphoma are classical Hodgkin lymphoma and nodular lymphocyte-predominant Hodgkin lymphoma. Symptoms include the painless enlargement of lymph nodes, spleen, or other immune tissue. Other symptoms include fever, weight loss, fatigue, or night sweats. Also called Hodgkin disease.

holmium Ho 166 DOTMP    listen   (HOLE-mee-um ...)
A drug containing a radioactive isotope that is used in the diagnosis and treatment of cancer.

holy thistle    listen   (... THIH-sul)
A plant whose leaves, stems, and flowers have been used in some cultures to treat certain medical problems. Holy thistle may have anti-inflammatory and anticancer effects. The scientific name is Cnicus benedictus. Also called blessed thistle, cardin, spotted thistle, and St. Benedict's thistle.

homeopathic medicine    listen   (HOH-mee-uh-PA-thik MEH-dih-sin)
An alternative approach to medicine based on the belief that natural substances, prepared in a special way and used most often in very small amounts, restore health. According to these beliefs, in order for a remedy to be effective, it must cause in a healthy person the same symptoms being treated in the patient. Also called homeopathy.

homeopathy    listen   (HOH-mee-AH-puh-thee)
An alternative approach to medicine based on the belief that natural substances, prepared in a special way and used most often in very small amounts, restore health. According to these beliefs, in order for a remedy to be effective, it must cause in a healthy person the same symptoms being treated in the patient. Also called homeopathic medicine.

homeostasis    listen   (HOH-mee-oh-STAY-sis)
A state of balance among all the body systems needed for the body to survive and function correctly. In homeostasis, body levels of acid, blood pressure, blood sugar, electrolytes, energy, hormones, oxygen, proteins, and temperature are constantly adjusted to respond to changes inside and outside the body, to keep them at a normal level.

homeostatic    listen   (HOH-mee-oh-STA-tik)
Having to do with homeostasis, which is a state of balance among all the body systems, needed for the body to function correctly.

homoharringtonine    listen   (hoh-moh-HAYR-ing-tuh-neen)
A drug used to treat certain types of chronic myelogenous leukemia (CML) that have not gotten better after treatment with other anticancer drugs. It is also being studied in the treatment of other types of cancer. Homoharringtonine blocks certain proteins involved in cancer cell growth and may kill cancer cells. It is a type of plant alkaloid. Also called omacetaxine mepesuccinate and Synribo.

hookah    listen   (HOOK-uh)
A device used to smoke a special type of tobacco that comes in different flavors. In a hookah, charcoal is used to heat the tobacco. The smoke from the heated tobacco is cooled by passing it through a water-filled bowl. It is then inhaled through a flexible tube with a mouthpiece. Hookah tobacco smoke contains nicotine and many cancer-causing chemicals that are harmful to both smokers and nonsmokers. Hookah smoking can lead to nicotine addiction and can cause many of the same health problems as cigarette smoking. Hookah smoking is not safer than cigarette smoking. Also called water pipe.

hormonal therapy    listen   (hor-MOH-nul THAYR-uh-pee)
Treatment that adds, blocks, or removes hormones. For certain conditions (such as diabetes or menopause), hormones are given to adjust low hormone levels. To slow or stop the growth of certain cancers (such as prostate and breast cancer), synthetic hormones or other drugs may be given to block the body’s natural hormones. Sometimes surgery is needed to remove the gland that makes a certain hormone. Also called endocrine therapy, hormone therapy, and hormone treatment.

hormone    listen   (HOR-mone)
One of many substances made by glands in the body. Hormones circulate in the bloodstream and control the actions of certain cells or organs. Some hormones can also be made in the laboratory.

hormone receptor    listen   (HOR-mone reh-SEP-ter)
A cell protein that binds a specific hormone. The hormone receptor may be on the surface of the cell or inside the cell. Many changes take place in a cell after a hormone binds to its receptor.

hormone receptor test    listen   (HOR-mone reh-SEP-ter test)
A test to measure the amount of certain proteins, called hormone receptors, in cancer tissue. Hormones can attach to these proteins. A high level of hormone receptors may mean that hormones help the cancer grow.

hormone replacement therapy    listen   (HOR-mone reh-PLAYS-ment THAYR-uh-pee)
Hormones (estrogen, progesterone, or both) given to women after menopause to replace the hormones no longer produced by the ovaries. Also called HRT and menopausal hormone therapy.

hormone responsive    listen   (HOR-mone reh-SPONT-siv)
In oncology, describes cancer that responds to hormone treatment.

hormone therapy    listen   (HOR-mone THAYR-uh-pee)
Treatment that adds, blocks, or removes hormones. For certain conditions (such as diabetes or menopause), hormones are given to adjust low hormone levels. To slow or stop the growth of certain cancers (such as prostate and breast cancer), synthetic hormones or other drugs may be given to block the body’s natural hormones. Sometimes surgery is needed to remove the gland that makes a certain hormone. Also called endocrine therapy, hormonal therapy, and hormone treatment.

hormone treatment    listen   (HOR-mone TREET-ment)
Treatment that adds, blocks, or removes hormones. For certain conditions (such as diabetes or menopause), hormones are given to adjust low hormone levels. To slow or stop the growth of certain cancers (such as prostate and breast cancer), synthetic hormones or other drugs may be given to block the body’s natural hormones. Sometimes surgery is needed to remove the gland that makes a certain hormone. Also called endocrine therapy, hormonal therapy, and hormone therapy.

hormone-refractory    listen   (HOR-mone-reh-FRAK-tor-ee)
In medicine, describes a disease or condition that does not respond to treatment with hormones. Also called hormone-resistant.

hormone-resistant    listen   (HOR-mone-reh-ZIH-stunt)
In medicine, describes a disease or condition that does not respond to treatment with hormones. Also called hormone-refractory.

Horner syndrome    listen   (...SIN-drome)
A condition in which one side of the face is flushed, does not produce sweat, and has a constricted pupil and drooping eyelid. It can be caused by an injury to, or paralysis of, nerves in the neck, or by a tumor.

hospice    listen   (HOS-pis)
A program that provides special care for people who are near the end of life and for their families, either at home, in freestanding facilities, or within hospitals.

host cell    listen   (... sel)
A cell that is infected by a virus or another type of microorganism.

hot flash    listen   (hot flash)
A sudden, temporary onset of body warmth, flushing, and sweating (often associated with menopause).

hot nodule    listen   (hot NAH-jool)
When radioactive material is used to examine the thyroid with a scanner, nodules that collect more radioactive material than the surrounding thyroid tissue are considered "hot." Hot nodules are rarely malignant. Hot nodules are sometimes called hyperfunctioning nodules.

hotspot    listen   (hot-spot)
In genetics, an area of DNA that is likely to mutate (change).

HPPH      
2-(1-hexyloxyethyl)-2-devinyl pyropheophorbide-a. A drug that is used in photodynamic therapy that is absorbed by tumor cells; when exposed to light, it becomes active and kills the cancer cells.

HPV      
A type of virus that can cause abnormal tissue growth (for example, warts) and other changes to cells. Infection for a long time with certain types of HPV can cause cervical cancer. HPV may also play a role in some other types of cancer, such as anal, vaginal, vulvar, penile, oropharyngeal, and squamous cell skin cancers. Also called human papillomavirus.

HPV DNA test    listen   (... test)
A laboratory test in which cells are scraped from the cervix to look for DNA of human papillomaviruses (HPV). HPV can cause abnormal tissue growth (for example, warts) and other changes to cells. Infection for a long time with certain types of HPV can cause cervical cancer. HPV can also play a role in other types of cancer, such as cancers of the anus, vagina, vulva, penis, and oropharynx. Also called human papillomavirus DNA test.

HPV RNA test    listen   (… test)
A laboratory test in which cells are scraped from the cervix to look for RNA of the most common types of human papillomavirus (HPV). Certain types of HPV may cause abnormal tissue growth, such as warts, and other changes to cells. Infection for a long time with other types of HPV may cause cervical cancer. An HPV RNA test may be done with a Pap test to check for HPV infection and cervical cancer. HPV infection may also cause other types of cancer, such as cancers of the anus, vagina, vulva, penis, and oropharynx. Also called human papillomavirus RNA test.

HPV test      
A laboratory test in which cells are tested for DNA or RNA from certain types of human papillomavirus (HPV) that are known to cause cervical cancer. These high-risk types of HPV can also cause other types of cancer, including cancers of the anus, vagina, vulva, penis, and oropharynx. An HPV test may be done at the same time as a Pap test for cervical cancer screening in women aged 30 to 65 years. An HPV test may also be done after certain abnormal Pap test results. Also called human papillomavirus test.

HPV vaccine    listen   (... vak-SEEN)
A vaccine used to prevent genital warts, anal cancer, cervical cancer, vulvar cancer, and vaginal cancer caused by certain types of human papillomavirus (HPV). It is also used to prevent lesions that are caused by those viruses and that can lead to anal, cervical, vulvar, or vaginal cancer. Also called human papillomavirus vaccine.

HPV/Pap cotest      
A procedure in which a human papillomavirus (HPV) test and a Pap test are done at the same time to check for cervical cancer. The HPV test looks for DNA or RNA from certain high-risk types of HPV in samples of cells taken from the cervix. The Pap test checks for cervical cancer cells and cell changes that may lead to cervical cancer. The same cell sample may be used for both the HPV test and the Pap test. Women aged 30 to 65 years may have an HPV/Pap cotest every 5 years. Cotesting is more likely to find abnormal cells or cervical cancer than a Pap test alone is.

Hras gene    listen   (… jeen)
A gene that may cause cancer when it is mutated (changed). The Hras gene makes the HRAS protein, which is involved in cell signaling pathways, cell growth, and apoptosis (cell death). Agents that block the actions of the mutated Hras gene or its protein in cancer cells may stop the growth of cancer. Also called H-ras gene.

HRT      
Hormones (estrogen, progesterone, or both) given to women after menopause to replace the hormones no longer produced by the ovaries. Also called hormone replacement therapy and menopausal hormone therapy.

HSIL      
Cells of the uterine cervix that are moderately or severely abnormal and may become cancer. Also called high-grade squamous intraepithelial lesion.

HSP      
One of a group of proteins that help protect cells from stresses such as heat, cold, and low amounts of oxygen or glucose (sugar). HSPs help other proteins function in normal cells and may be present at high levels in cancer cells. Blocking the activity of a HSP called HSP90 is being studied in the treatment of cancer. Other HSPs including HSP70 and gp96 are being studied in vaccines to treat cancer. Also called heat-shock protein and stress protein.

HSV      
A type of virus that causes herpes infections and has DNA as its genetic material. There are two types of HSVs. Infections with type 1 viruses cause cold sores on the lips or nostrils. Infections with type 2 viruses cause sores on the genitals (external and internal sex organs and glands). Also called herpes simplex virus, HHV, and human herpesvirus.

HTLV-1      
A type of virus that infects T cells (a type of white blood cell) and can cause leukemia and lymphoma. HTLV-1 is spread by sharing syringes or needles, through blood transfusions or sexual contact, and from mother to child during birth or breast-feeding. Also called human T-cell leukemia virus type 1 and human T-cell lymphotropic virus type 1.

hu14.18-interleukin-2 fusion protein    listen   (… in-ter-LOO-kin-2 FYOO-zhun PROH-teen)
An anticancer drug in which hu14.18, a monoclonal antibody, is combined with interleukin-2. The monoclonal antibody binds to the cancer cells and delivers IL-2, which stimulates the immune system to destroy the cancer cells.

Hu3S193      
A monoclonal antibody that is being studied in the treatment of some types of cancer. Monoclonal antibodies are made in the laboratory and can locate and bind to substances in the body, including cancer cells. Hu3S193 binds to the protein Lewis(y), which is found on colon, breast, lung, ovary, and prostate cancer cells.

HuAFP31      
A monoclonal antibody being studied in the treatment of several types of cancer. Monoclonal antibodies are made in the laboratory and can locate and bind to substances in the body, including cancer cells. HuAFP31 attaches to tumor cells that make alpha fetoprotein (AFP). This makes it easier for T cells to find and kill the tumor cells.

Huang Lian    listen   (hwang lyan)
A Chinese herb that has been used as a treatment for a variety of medical problems. It is being studied as an anticancer drug.

huC242-DM4      
A substance being studied in the treatment of some types of cancer. It is made by linking the monoclonal antibody huC242 to a toxic substance called maytansinoid DM4. The monoclonal antibody binds to the surfaces of cancer cells and the maytansinoid DM4 enters the cells and blocks their growth. It is a type of immunotoxin. Also called maytansinoid DM4-conjugated humanized monoclonal antibody huC242.

HuHMFG1      
A monoclonal antibody that binds to the protein MUC1, which is found on breast, ovarian, pancreatic, gastric, and colon cancer cells. Monoclonal antibodies are made in the laboratory and can locate and bind to substances in the body, including cancer cells. HuHMFG1 is being studied in the treatment of some types of cancer.

HuLuc63      
A monoclonal antibody being studied in the treatment of advanced multiple myeloma. Monoclonal antibodies are made in the laboratory and can locate and bind to substances in the body, including cancer cells. HuLuc63 binds to CS1, a protein that is found mainly on the surface of multiple myeloma cells.

human corticotropin-releasing factor    listen   (HYOO-mun KOR-tih-koh-TROH-pin-reh-LEE-sing FAK-ter)
A substance being studied in the treatment of brain cancer. It is made naturally by the hypothalamus (a part of the brain) and can also be made in the laboratory. Human corticotropin-releasing factor may help reduce symptoms caused by edema (swelling) of the brain. It is a type of neurohormone. Also called hCRF.

human EGF receptor 2    listen   (HYOO-mun … reh-SEP-ter ...)
A protein involved in normal cell growth. It is found on some types of cancer cells, including breast and ovarian. Cancer cells removed from the body may be tested for the presence of human EGF receptor 2 to help decide the best type of treatment. Human EGF receptor 2 is a type of receptor tyrosine kinase. Also called c-erbB-2, HER2/neu, and human epidermal growth factor receptor 2.

human epidermal growth factor receptor 2 positive    listen   (HYOO-mun eh-pih-DER-mul grothe FAK-ter reh-SEP-ter … PAH-zih-tiv)
Describes cancer cells that have too much of a protein called HER2 on their surface. In normal cells, HER2 helps to control cell growth. When it is made in larger than normal amounts by cancer cells, the cells may grow more quickly and be more likely to spread to other parts of the body. Checking to see if a cancer is human epidermal growth factor receptor 2 positive may help plan treatment, which may include drugs that kill human epidermal growth factor receptor 2 positive cancer cells. Cancers that may be human epidermal growth factor receptor 2 positive include breast, bladder, pancreatic, ovarian, and stomach cancers. Also called c-erbB-2 positive and HER2 positive.

human epidermal growth factor receptor 2    listen   (HYOO-mun eh-pih-DER-mul grothe FAK-ter reh-SEP-ter ...)
A protein involved in normal cell growth. It is found on some types of cancer cells, including breast and ovarian. Cancer cells removed from the body may be tested for the presence of human epidermal growth factor receptor 2 to help decide the best type of treatment. Human epidermal growth factor receptor 2 is a type of receptor tyrosine kinase. Also called c-erbB-2, HER2/neu, and human EGF receptor 2.

human epididymis protein 4    listen   (HYOO-mun eh-pih-DIH-dih-mis PROH-teen …)
A protein found on cells that line the lungs and reproductive organs, such as the ovaries. Human epididymis protein 4 may be found in higher than normal amounts in patients with some types of cancer, including ovarian epithelial cancer. Measuring the amount of human epididymis protein 4 in the blood may help plan cancer treatment or find out if cancer is getting worse or has come back. It is a type of tumor marker. Also called HE4.

human herpesvirus    listen   (HYOO-mun HER-peez-VY-rus)
A type of virus that causes herpes infections and has DNA as its genetic material. There are two types of human herpesviruses. Infections with type 1 viruses cause cold sores on the lips or nostrils. Infections with type 2 viruses cause sores on the genitals (external and internal sex organs and glands). Also called herpes simplex virus, HHV, and HSV.

human herpesvirus 8    listen   (HYOO-mun HER-peez-VY-rus...)
A type of virus that causes Kaposi sarcoma (a rare cancer in which lesions grow in the skin, lymph nodes, lining of the mouth, nose, and throat, and other tissues of the body). Human herpesvirus 8 also causes certain types of lymphoma (cancer that begins in cells of the immune system). Also called HHV8, Kaposi sarcoma-associated herpesvirus, and KSHV.

human immunodeficiency virus    listen   (HYOO-mun IH-myoo-noh-dih-FIH-shun-see VY-rus)
The cause of acquired immunodeficiency syndrome (AIDS). Also called HIV.

human leukocyte antigen    listen   (HYOO-mun LOO-koh-site AN-tih-jen)
A type of molecule found on the surface of most cells in the body. Human leukocyte antigens play an important part in the body's immune response to foreign substances. They make up a person’s tissue type, which varies from person to person. Human leukocyte antigen tests are done before a donor stem cell or organ transplant, to find out if tissues match between the donor and the person receiving the transplant. Also called HLA and human lymphocyte antigen.

human leukocyte antigen matching    listen   (HYOO-mun LOO-koh-site AN-tih-jen MA-ching)
A process in which blood or tissue samples are tested for human leukocyte antigens (HLAs). HLAs are molecules found on the surface of most cells in the body. They make up a person’s tissue type, which varies from person to person. They play an important part in the body's immune response to foreign substances. Human leukocyte antigen matching is done before a donor stem cell or organ transplant to find out if tissues match between the donor and the person receiving the transplant. Also called HLA matching.

human lymphocyte antigen    listen   (HYOO-mun LIM-foh-site AN-tih-jen)
A type of molecule found on the surface of most cells in the body. Human lymphocyte antigens play an important part in the body's immune response to foreign substances. They make up a person’s tissue type, which varies from person to person. Human lymphocyte antigen tests are done before a donor stem cell or organ transplant, to find out if tissues match between the donor and the person receiving the transplant. Also called HLA and human leukocyte antigen.

human papillomavirus    listen   (HYOO-mun PA-pih-LOH-muh-VY-rus)
A type of virus that can cause abnormal tissue growth (for example, warts) and other changes to cells. Infection for a long time with certain types of human papillomavirus can cause cervical cancer. Human papillomavirus may also play a role in some other types of cancer, such as anal, vaginal, vulvar, penile, oropharyngeal, and squamous cell skin cancers. Also called HPV.

human papillomavirus DNA test    listen   (HYOO-mun PA-pih-LOH-muh-VY-rus …)
A laboratory test in which cells are scraped from the cervix to look for DNA of human papillomaviruses (HPV). HPV can cause abnormal tissue growth (for example, warts) and other changes to cells. Infection for a long time with certain types of HPV can cause cervical cancer. HPV can also play a role in other types of cancer, such as cancers of the anus, vagina, vulva, penis, and oropharynx. Also called HPV DNA test.

human papillomavirus RNA test    listen   (HYOO-mun PA-pih-LOH-muh-VY-rus … test)
A laboratory test in which cells are scraped from the cervix to look for RNA of the most common types of human papillomavirus (HPV). Certain types of HPV may cause abnormal tissue growth, such as warts, and other changes to cells. Infection for a long time with other types of HPV may cause cervical cancer. A human papillomavirus RNA test may be done with a Pap test to check for HPV infection and cervical cancer. HPV infection may also cause other types of cancer, such as cancers of the anus, vagina, vulva, penis, and oropharynx. Also called HPV RNA test.

human papillomavirus test    listen   (HYOO-mun PA-pih-LOH-muh-VY-rus …)
A laboratory test in which cells are tested for DNA or RNA from certain types of human papillomavirus (HPV) that are known to cause cervical cancer. These high-risk types of HPV can also cause other types of cancer, including cancers of the anus, vagina, vulva, penis, and oropharynx. A human papillomavirus test may be done at the same time as a Pap test for cervical cancer screening in women aged 30 to 65 years. A human papillomavirus test may also be done after certain abnormal Pap test results. Also called HPV test.

human papillomavirus vaccine    listen   (HYOO-mun PA-pih-LOH-muh-VY-rus vak-SEEN)
A vaccine used to prevent genital warts, anal cancer, cervical cancer, vulvar cancer, and vaginal cancer caused by certain types of human papillomavirus (HPV). It is also used to prevent lesions that are caused by those viruses and that can lead to anal, cervical, vulvar, or vaginal cancer. Also called HPV vaccine.

human participant protection regulations    listen   (HYOO-mun par-TIH-sih-punt proh-TEK-shun REH-gyoo-LAY-shunz)
Laws set by the U.S. Department of Health and Human Services (DHHS) to protect a person from risks in research studies that any federal agency or department has a part in. Also called 45 CFR 46, 45 Code of Federal Regulations Part 46, and Protection of Human Subjects.

human T-cell leukemia virus type 1    listen   (HYOO-mun T-sel loo-KEE-mee-uh VY-rus...)
A type of virus that infects T cells (a type of white blood cell) and can cause leukemia and lymphoma. Human T-cell leukemia virus type 1 is spread by sharing syringes or needles, through blood transfusions or sexual contact, and from mother to child during birth or breast-feeding. Also called HTLV-1 and human T-cell lymphotropic virus type 1.

human T-cell lymphotropic virus type 1    listen   (HYOO-mun T-sel LIM-foh-TROH-pik VY-rus...)
A type of virus that infects T cells (a type of white blood cell) and can cause leukemia and lymphoma. Human T-cell lymphotropic virus type 1 is spread by sharing syringes or needles, through blood transfusions or sexual contact, and from mother to child during birth or breast-feeding. Also called HTLV-1 and human T-cell leukemia virus type 1.

humanized monoclonal antibody    listen   (HYOO-muh-nized MAH-noh-KLOH-nul AN-tee-BAH-dee)
A type of antibody made in the laboratory by combining a human antibody with a small part of a mouse or rat monoclonal antibody. The mouse or rat part of the antibody binds to the target antigen, and the human part makes it less likely to be destroyed by the body's immune system.

humanized monoclonal antibody MEDI-522    listen   (HYOO-muh-nized MAH-noh-KLOH-nul AN-tee-BAH-dee …)
A substance being studied in the treatment of some types of cancer and other conditions. Humanized monoclonal antibody MEDI-522 binds to a protein on the surface of blood vessels and may prevent the growth of new blood vessels that tumors need to grow. It may also prevent the spread of cancer. It is a type of antiangiogenesis agent, a type of metastasis inhibitor, and a type of monoclonal antibody. Also called Abegrin, etaracizumab, and MEDI-522.

HuMax-CD20      
A drug used to treat chronic lymphocytic leukemia (CLL) that has not gotten better with other anticancer drugs. It is also used with chlorambucil in patients who have not already been treated and cannot receive certain anticancer drugs. It is also being studied in the treatment of other types of cancer. HuMax-CD20 binds to a protein called CD20, which is found on B cells (a type of white blood cell) and some types of leukemia and lymphoma cells. This may help the immune system kill cancer cells. HuMax-CD20 is a type of monoclonal antibody. Also called Arzerra and ofatumumab.

humidifier    listen   (hyoo-MIH-dih-fy-er)
A machine that puts moisture in the air.

humor therapy    listen   (HYOO-mer THAYR-uh-pee)
A type of therapy that uses humor to help relieve pain and stress and improve a person’s sense of well-being. It may be used to help people cope with a serious disease, such as cancer. Humor therapy may include laughter exercises, clowns, and comedy movies, books, games, and puzzles. It is a type of complementary therapy. Also called laughter therapy.

Hurthle cell neoplasm    listen   (HEERT-leh...NEE-oh-PLA-zum)
An uncommon type of thyroid tumor that can be benign or malignant.

Hycamtin    listen   (hy-KAM-tin)
A drug used to treat certain types of ovarian cancer, lung cancer, and cervical cancer. Hycamtin is a type of topoisomerase inhibitor. Also called topotecan and topotecan hydrochloride.

hydatidiform mole    listen   (HY-duh-TIH-dih-form...)
A slow-growing tumor that develops from trophoblastic cells (cells that help an embryo attach to the uterus and help form the placenta) after fertilization of an egg by a sperm. A hydatidiform mole contains many cysts (sacs of fluid). It is usually benign (not cancer) but it may spread to nearby tissues (invasive mole). It may also become a malignant tumor called choriocarcinoma. Hydatidiform mole is the most common type of gestational trophoblastic tumor. Also called molar pregnancy.

hydration    listen   (hy-DRAY-shun)
The process of combining with water. In medicine, the process of giving fluids needed by the body.

hydrazine sulfate    listen   (HY-druh-ZEEN SUL-fayt)
A substance that has been studied as a treatment for cancer and as a treatment for cachexia (body wasting) associated with advanced cancer.

hydrocarbon    listen   (HY-droh-KAR-bun)
A substance made of only hydrogen and carbon. Examples of hydrocarbons are coal, petroleum, natural gas and tar. They are used as energy sources. Being exposed to hydrocarbons may increase the risk of certain types of cancer.

hydrocephalus    listen   (HY-droh-SEH-fuh-lus)
The abnormal buildup of cerebrospinal fluid in the ventricles of the brain.

hydrocodone bitartrate    listen   (HY-droh-KOH-done by-TAR-trayt)
A drug used to treat moderate to severe pain and cough. Hydrocodone bitartrate is made from codeine and binds to opioid receptors in the central nervous system. It is a type of analgesic agent, a type of antitussive, and a type of opiate.

hydrocortisone    listen   (HY-droh-KOR-tih-sone)
A drug used to relieve the symptoms of certain hormone shortages and to suppress an immune response.

hydrogen peroxide    listen   (HY-droh-jen peh-ROK-side)
A chemical used in bleaches, dyes, cleansers, antiseptics, and disinfectants. In a concentrated form, it is toxic and irritating to tissues.

hydrolysis    listen   (hy-DRAH-lih-sis)
A chemical reaction that uses water to break down a compound.

hydromorphone hydrochloride    listen   (HY-droh-MOR-fone HY-droh-KLOR-ide)
A drug used to treat moderate to severe pain. It may also be used to treat certain types of cough. Hydromorphone hydrochloride is made from morphine and binds to opioid receptors in the central nervous system. It is a type of opioid and a type of analgesic agent. Also called Dilaudid, Exalgo, and Hydrostat IR.

hydronephrosis    listen   (HY-droh-neh-FROH-sis)
Abnormal enlargement of a kidney, which may be caused by blockage of the ureter (such as by a kidney stone) or chronic kidney disease that prevents urine from draining into the bladder.

Hydrostat IR    listen   (HY-droh-STAT …)
A drug used to treat moderate to severe pain. It may also be used to treat certain types of cough. Hydrostat IR is made from morphine and binds to opioid receptors in the central nervous system. It is a type of opioid and a type of analgesic agent. Also called Dilaudid, Exalgo, and hydromorphone hydrochloride.

hydroureter    listen   (HY-droh-YER-eh-ter)
Abnormal enlargement of the ureter caused by any blockage that prevents urine from draining into the bladder.

hydroxychloroquine    listen   (hy-DROK-see-KLOR-oh-kwin)
A substance that decreases immune responses in the body. It is used to treat some autoimmune diseases, and is being studied as a treatment for graft-versus-host disease. Hydroxychloroquine belongs to the family of drugs called antiprotozoals.

hydroxydaunorubicin    listen   (hy-DROK-see-DAW-noh-ROO-bih-sin)
A drug that is used to treat many types of cancer and is being studied in the treatment of other types of cancer. Hydroxydaunorubicin comes from the bacterium Streptomyces peucetius. It damages DNA and may kill cancer cells. It is a type of anthracycline antitumor antibiotic. Also called Adriamycin PFS, Adriamycin RDF, doxorubicin, doxorubicin hydrochloride, and Rubex.

hydroxymethylglutaryl-coenzyme A reductase inhibitor    listen   (hy-DROK-see-MEH-thul-GLOO-tuh-ril-koh-EN-zime A ree-DUK-tays in-HIH-bih-ter)
A substance that blocks an enzyme needed by the body to make cholesterol and lowers the amount of cholesterol in the blood. Hydroxymethylglutaryl-coenzyme A reductase inhibitor drugs are called statins. Also called HMG-CoA reductase inhibitor.

hydroxyurea    listen   (hy-DROK-see-yoo-REE-uh)
An anticancer drug that belongs to the family of drugs called antimetabolites.

hygiene    listen   (HY-jeen)
The science of health, and the practice of cleanliness that promotes good health and well-being.

hyper-CVAD    listen   (HY-per ...)
An abbreviation for a chemotherapy combination used to treat some types of acute lymphoblastic leukemia (ALL) and non-Hodgkin lymphoma (NHL). Hyper-CVAD includes the drugs cyclophosphamide, vincristine sulfate, doxorubicin hydrochloride (Adriamycin), and dexamethasone. It also includes the drugs methotrexate and cytarabine. It is given as hyperfractionated therapy, in which the total dose of the drugs is divided into small doses and given more than once a day. Also called hyper-CVAD regimen.

hyper-CVAD regimen    listen   (HY-per ... REH-jih-men)
An abbreviation for a chemotherapy combination used to treat some types of acute lymphoblastic leukemia (ALL) and non-Hodgkin lymphoma (NHL). Hyper-CVAD regimen includes the drugs cyclophosphamide, vincristine sulfate, doxorubicin hydrochloride (Adriamycin), and dexamethasone. It also includes the drugs methotrexate and cytarabine. It is given as hyperfractionated therapy, in which the total dose of the drugs is divided into small doses and given more than once a day. Also called hyper-CVAD.

hyperactivity    listen   (HY-per-ak-TIH-vih-tee)
A higher than normal level of activity. Hyperactivity can be used to describe the increased action of a body function, such as hormone production, or behavior. A person who is hyperactive may seem to be always moving or fidgeting, impulsive, unable to concentrate, and talking too much.

hyperalimentation    listen   (HY-per-A-lih-men-TAY-shun)
A form of nutrition that is delivered into a vein. Hyperalimentation does not use the digestive system. It may be given to people who are unable to absorb nutrients through the intestinal tract because of vomiting that won't stop, severe diarrhea, or intestinal disease. It may also be given to those undergoing high-dose chemotherapy or radiation and bone marrow transplantation. It is possible to give all of the protein, calories, vitamins and minerals a person needs using hyperalimentation. Also called parenteral nutrition, total parenteral nutrition, and TPN.

hyperbaric oxygen    listen   (HY-per-BAYR-ik OK-sih-jen)
Oxygen that is given at a pressure that is higher than the pressure of the atmosphere at sea level. In medicine, breathing hyperbaric oxygen increases the amount of oxygen in the body. It is used in treating certain kinds of wounds, injuries, and infections. It is also used to treat carbon monoxide poisoning and other conditions in which the tissues are not getting enough oxygen. It is being studied in the treatment of some types of cancer. Hyperbaric oxygen may increase the amount of oxygen in cancer cells, which may make them easier to kill with radiation therapy and chemotherapy. It is a type of radiosensitizing agent and a type of chemosensitizing agent.

hyperbilirubinemia    listen   (HY-per-bih-lih-ROO-bih-NEE-mee-uh)
Higher-than-normal amount of bilirubin in the blood. Bilirubin is a substance formed when red blood cells break down.

hypercalcemia    listen   (HY-per-kal-SEE-mee-uh)
Higher than normal levels of calcium in the blood. Some types of cancer increase the risk of hypercalcemia.

hyperfractionated radiation therapy    listen   (HY-per-FRAK-shuh-NAY-ted RAY-dee-AY-shun THAYR-uh-pee)
Radiation treatment in which the total dose of radiation is divided into small doses and treatments are given more than once a day. Hyperfractionated radiation therapy is given over the same period of time (days or weeks) as standard radiation therapy. Also called superfractionated radiation therapy.

hyperfractionation    listen   (HY-per-FRAK-shuh-NAY-shun)
A treatment schedule in which the total dose of radiation or chemotherapy is divided into small doses and treatments are given more than once a day.

hyperglycemia    listen   (HY-per-gly-SEE-mee-uh)
Higher than normal amount of glucose (a type of sugar) in the blood. Hyperglycemia can be a sign of diabetes or other conditions. Also called high blood sugar.

Hypericum perforatum    listen   (hy-PAYR-ih-kum per-fuh-RAY-tum)
An herbal product sold as an over-the-counter treatment for depression. It is being studied for its ability to lessen certain side effects of cancer treatment. Also called St. John's wort.

hyperkeratosis    listen   (HY-per-KAYR-uh-TOH-sis)
A condition marked by thickening of the outer layer of the skin, which is made of keratin (a tough, protective protein). It can result from normal use (corns, calluses), chronic inflammation (eczema), or genetic disorders (X-linked ichthyosis, ichthyosis vulgaris).

hypernephroma    listen   (HY-per-neh-FROH-muh)
The most common type of kidney cancer. It begins in the lining of the renal tubules in the kidney. The renal tubules filter the blood and produce urine. Also called renal cell adenocarcinoma, renal cell cancer, and renal cell carcinoma.

hyperparathyroidism    listen   (HY-per-PAYR-uh-THY-roy-dih-zum)
A condition in which the parathyroid gland (one of four pea-sized organs found on the thyroid) makes too much parathyroid hormone. This causes a loss of calcium from the bones and an increased level of calcium in the blood. Symptoms include bone pain and kidney problems.

hyperplasia    listen   (HY-per-PLAY-zhuh)
An abnormal increase in the number of normal cells in an organ or tissue.

hypersensitivity    listen   (HY-per-SEN-sih-tih-vih-tee)
An exaggerated response by the immune system to a drug or other substance.

hypertension    listen   (HY-per-TEN-shun)
A blood pressure of 140/90 or higher. Hypertension usually has no symptoms. It can harm the arteries and cause an increase in the risk of stroke, heart attack, kidney failure, and blindness. Also called high blood pressure.

hyperthermia    listen   (HY-per-THER-mee-uh)
Abnormally high body temperature. This may be caused as part of treatment, by an infection, or by exposure to heat.

hyperthermia therapy    listen   (HY-per-THER-mee-uh THAYR-uh-pee)
A type of treatment in which body tissue is exposed to high temperatures to damage and kill cancer cells or to make cancer cells more sensitive to the effects of radiation and certain anticancer drugs.

hyperthermic perfusion    listen   (HY-per-THER-mik per-FYOO-zhun)
A procedure in which a warmed solution containing anticancer drugs is used to bathe, or is passed through the blood vessels of, the tissue or organ containing the tumor.

hyperthyroidism    listen   (HY-per-THY-roy-dih-zum)
Too much thyroid hormone. Symptoms include weight loss, chest pain, cramps, diarrhea, and nervousness. Also called overactive thyroid.

hyperuricemia    listen   (HY-per-YOO-rih-SEE-mee-uh)
A buildup of uric acid (a byproduct of metabolism) in the blood. Hyperuricemia is a side effect of some anticancer drugs.

hypervascular    listen   (HY-per-VAS-kyoo-ler)
Having a large number of blood vessels.

hypnosis    listen   (hip-NOH-sis)
A trance-like state in which a person becomes more aware and focused on particular thoughts, feelings, images, sensations, or behaviors. While under hypnosis, a person may feel calm, relaxed, and more open to suggestion. Hypnosis is usually done with the help of a specially trained therapist. It may be used to help relieve stress, anxiety, and pain, and to help a person quit smoking or lose weight. Hypnosis is a type of complementary and alternative medicine (CAM).

hypofractionated radiation therapy    listen   (HY-poh-FRAK-shuh-NAY-ted RAY-dee-AY-shun THAYR-uh-pee)
Radiation treatment in which the total dose of radiation is divided into large doses and treatments are given once a day or less often. Hypofractionated radiation therapy is given over a shorter period of time (fewer days or weeks) than standard radiation therapy.

hypofractionation    listen   (HY-poh-FRAK-shuh-NAY-shun)
A treatment schedule in which the total dose of radiation is divided into large doses and treatments are given once a day or less often.

hypogammaglobulinemia    listen   (HY-poh-GA-muh-GLAH-byoo-lih-NEE-mee-uh)
A condition in which the level of immunoglobulins (antibodies) in the blood is low and the risk of infection is high.

hypoglycemia    listen   (HY-poh-gly-SEE-mee-uh)
Abnormally low blood sugar.

hypomagnesemia    listen   (HY-poh-MAG-neh-SEE-mee-uh)
Lower-than-normal amount of magnesium in the blood.

hyponatremia    listen   (HY-poh-nuh-TREE-mee-uh)
Lower-than-normal amount of sodium in the blood.

hypopharyngeal cancer    listen   (HY-poh-fuh-RIN-jee-ul KAN-ser)
Cancer that forms in tissues of the hypopharynx (the bottom part of the throat). The most common type is squamous cell carcinoma (cancer that begins in flat cells lining the hypopharynx).

hypopharynx    listen   (HY-poh-FAYR-inx)
The bottom part of the throat. Cancer of the hypopharynx is also known as hypopharyngeal cancer.

hypophosphatemia    listen   (HY-poh-FOS-fuh-TEE-mee-uh)
Lower-than-normal amount of phosphorus in the blood.

hypospadias    listen   (HY-poh-SPAY-dee-us)
A birth defect in which the opening of the urethra (the tube through which urine leaves the body) is not in its normal place. In males with hypospadias, the urethra opens on the underside of the penis or between the anus and the scrotum. In females with hypospadias, it opens into the vagina. Hypospadias is much more common in males than in females, and can be corrected by surgery. Children with hypospadias have an increased risk of developing Wilms tumor (a type of kidney cancer).

hypotension    listen   (HY-poh-TEN-shun)
Abnormally low blood pressure.

hypothalamus    listen   (HY-poh-THA-luh-mus)
The area of the brain that controls body temperature, hunger, and thirst.

hypothesis    listen   (hy-PAH-theh-sis)
A tentative proposal made to explain certain observations or facts that requires further investigation to be verified.

hypothyroidism    listen   (HY-poh-THY-roy-dih-zum)
Too little thyroid hormone. Symptoms include weight gain, constipation, dry skin, and sensitivity to the cold. Also called underactive thyroid.

hypoxemia    listen   (HY-pok-SEE-mee-uh)
A condition in which there is not enough oxygen in the blood.

hypoxia    listen   (hy-POK-see-uh)
A condition in which there is a decrease in the oxygen supply to a tissue. In cancer treatment, the level of hypoxia in a tumor may help predict the response of the tumor to the treatment.

hypoxic    listen   (hy-POK-sik)
Having too little oxygen.

hysterectomy    listen   (HIS-teh-REK-toh-mee)
Surgery to remove the uterus and, sometimes, the cervix. When the uterus and the cervix are removed, it is called a total hysterectomy. When only the uterus is removed, it is called a partial hysterectomy.

Hytrin    listen   (HY-trin)
A drug used to treat urinary problems caused by an enlarged prostate. It is also used to treat high blood pressure and is being studied in the treatment of other conditions. Hytrin relaxes muscle tissue in blood vessels and in the prostate. It is a type of alpha blocker. Also called terazosin and terazosin hydrochloride.

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