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Nausea and Vomiting (PDQ®)

Patient Version
Last Modified: 12/01/2011

Causes

Key Points for This Section


Chemotherapy and radiation therapy are the most common causes of nausea and vomiting in patients being treated for cancer.

Nausea is controlled by a part of the central nervous system that controls involuntary body functions (like the heart beating). Vomiting is a reflex controlled by a vomiting center in the brain. Vomiting can be triggered by smell, taste, anxiety, pain, motion, poor blood flow, irritation, or changes in the body caused by inflammation.

The most common causes of nausea and vomiting are:

Many factors increase the risk for nausea and vomiting.

Nausea and vomiting are more likely if the patient:



Glossary Terms

anxiety (ang-ZY-eh-tee)
Feelings of fear, dread, and uneasiness that may occur as a reaction to stress. A person with anxiety may sweat, feel restless and tense, and have a rapid heart beat. Extreme anxiety that happens often over time may be a sign of an anxiety disorder.
blood (blud)
A tissue with red blood cells, white blood cells, platelets, and other substances suspended in fluid called plasma. Blood takes oxygen and nutrients to the tissues, and carries away wastes.
blood poisoning (blud POY-zuh-ning)
Disease caused by the spread of bacteria and their toxins in the bloodstream. Also called septicemia and toxemia.
calcium (KAL-see-um)
A mineral needed for healthy teeth, bones, and other body tissues. It is the most common mineral in the body. A deposit of calcium in body tissues, such as breast tissue, may be a sign of disease.
central nervous system (SEN-trul NER-vus SIS-tem)
The brain and spinal cord. Also called CNS.
chemotherapy (KEE-moh-THAYR-uh-pee)
Treatment with drugs that kill cancer cells.
constipation (KON-stih-PAY-shun)
A condition in which stool becomes hard, dry, and difficult to pass, and bowel movements don’t happen very often. Other symptoms may include painful bowel movements, and feeling bloated, uncomfortable, and sluggish.
dehydration (dee-hy-DRAY-shun)
A condition caused by the loss of too much water from the body. Severe diarrhea or vomiting can cause dehydration.
drug (drug)
Any substance, other than food, that is used to prevent, diagnose, treat or relieve symptoms of a disease or abnormal condition. Also refers to a substance that alters mood or body function, or that can be habit-forming or addictive, especially a narcotic.
electrolyte (ee-LEK-troh-lite)
A substance that breaks up into ions (particles with electrical charges) when it is dissolved in water or body fluids. Some examples of ions are sodium, potassium, calcium, chloride, and phosphate. These ions help move nutrients into cells, help move waste out of cells, and help nerves, muscles, the heart, and the brain work the way they should.
fluid (FLOO-id)
A substance that flows smoothly and takes the shape of its container. Liquids and gases are fluids.
gastrointestinal tract (GAS-troh-in-TES-tih-nul trakt)
The stomach and intestines. The gastrointestinal tract is part of the digestive system, which also includes the salivary glands, mouth, esophagus, liver, pancreas, gallbladder, and rectum.
infection (in-FEK-shun)
Invasion and multiplication of germs in the body. Infections can occur in any part of the body and can spread throughout the body. The germs may be bacteria, viruses, yeast, or fungi. They can cause a fever and other problems, depending on where the infection occurs. When the body’s natural defense system is strong, it can often fight the germs and prevent infection. Some cancer treatments can weaken the natural defense system.
inflammation (IN-fluh-MAY-shun)
Redness, swelling, pain, and/or a feeling of heat in an area of the body. This is a protective reaction to injury, disease, or irritation of the tissues.
involuntary (in-VAH-lun-TAYR-ee)
An action that is not made by choice. In the body, involuntary actions (such as blushing) occur automatically, and cannot be controlled by choice.
kidney (KID-nee)
One of a pair of organs in the abdomen. Kidneys remove waste from the blood (as urine), produce erythropoietin (a substance that stimulates red blood cell production), and play a role in blood pressure regulation.
liver (LIH-ver)
A large organ located in the upper abdomen. The liver cleanses the blood and aids in digestion by secreting bile.
medicine (MEH-dih-sin)
Refers to the practices and procedures used for the prevention, treatment, or relief of symptoms of a diseases or abnormal conditions. This term may also refer to a legal drug used for the same purpose.
nausea (NAW-zee-uh)
A feeling of sickness or discomfort in the stomach that may come with an urge to vomit. Nausea is a side effect of some types of cancer therapy.
opioid (OH-pee-OYD)
A substance used to treat moderate to severe pain. Opioids are like opiates, such as morphine and codeine, but are not made from opium. Opioids bind to opioid receptors in the central nervous system. Opioids used to be called narcotics. An opioid is a type of alkaloid.
radiation therapy (RAY-dee-AY-shun THAYR-uh-pee)
The use of high-energy radiation from x-rays, gamma rays, neutrons, protons, and other sources to kill cancer cells and shrink tumors. Radiation may come from a machine outside the body (external-beam radiation therapy), or it may come from radioactive material placed in the body near cancer cells (internal radiation therapy). Systemic radiation therapy uses a radioactive substance, such as a radiolabeled monoclonal antibody, that travels in the blood to tissues throughout the body. Also called irradiation and radiotherapy.
tissue (TIH-shoo)
A group or layer of cells that work together to perform a specific function.
tumor (TOO-mer)
An abnormal mass of tissue that results when cells divide more than they should or do not die when they should. Tumors may be benign (not cancer), or malignant (cancer). Also called neoplasm.
vomit (VAH-mit)
To eject some or all of the contents of the stomach through the mouth.