Key Points for This Section

Essential thrombocythemia is a disease in which too many platelets are made in the bone marrow. Patients with essential thrombocythemia may have no symptoms. Certain factors affect prognosis (chance of recovery) and treatment options for essential thrombocythemia.

Essential thrombocythemia is a disease in which too many platelets are made in the bone marrow.

Essential thrombocythemia causes an abnormal increase in the number of platelets made in the blood and bone marrow.

Patients with essential thrombocythemia may have no symptoms.

Essential thrombocythemia often does not cause early symptoms. It is sometimes found during a routine blood test. The following symptoms may be caused by essential thrombocytopenia or by other conditions. A doctor should be consulted if any of these problems occur:

• Headache.
• Burning or tingling in the hands or feet.
• Redness and warmth of the hands or feet.
• Vision or hearing problems.

Platelets are sticky. When there are too many platelets, they may clump together and make it hard for the blood to flow. Clots may form in blood vessels and there may also be increased bleeding. These can cause serious health problems such as stroke or heart attack.

Certain factors affect prognosis (chance of recovery) and treatment options for essential thrombocythemia.

Prognosis (chance of recovery) and treatment options depend on the following:

• The age of the patient.
• Whether the patient has symptoms or other problems related to essential thrombocythemia.

Glossary Terms

Not normal. An abnormal lesion or growth may be cancerous, premalignant (likely to become cancer), or benign.

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.

A tube through which the blood circulates in the body. Blood vessels include a network of arteries, arterioles, capillaries, venules, and veins.

The soft, sponge-like tissue in the center of most bones. It produces white blood cells, red blood cells, and platelets.

CBC. A test to check the number of red blood cells, white blood cells, and platelets in a sample of blood. Also called blood cell count and CBC.

An increased number of thrombocytes (platelets) in the blood, without a known cause. Also called essential thrombocytosis.

A type of blood cell that helps prevent bleeding by causing blood clots to form. Also called a thrombocyte.

The likely outcome or course of a disease; the chance of recovery or recurrence.

In medicine, a loss of blood flow to part of the brain, which damages brain tissue. Strokes are caused by blood clots and broken blood vessels in the brain. Symptoms include dizziness, numbness, weakness on one side of the body, and problems with talking, writing, or understanding language. The risk of stroke is increased by high blood pressure, older age, smoking, diabetes, high cholesterol, heart disease, atherosclerosis (a build-up of fatty material and plaque inside the coronary arteries), and a family history of stroke.

An indication that a person has a condition or disease. Some examples of symptoms are headache, fever, fatigue, nausea, vomiting, and pain.