Essential thrombocythemia; Essential thrombocytosis
Primary thrombocythemia is the overproduction of platelets without a known cause. Platelets are essential for blood clotting.
Primary thrombocythemia is a disorder that slowly progresses. It is caused by too much growth of a type of cell that is used to make blood cells. Although the platelets are mostly affected, the red blood cells and white blood cells may also be involved.
The disease is in the same family of disorders as:
Usually it affects people in middle age. It can also be seen in younger patients, especially females under age 40.
People with this condition make too many platelets and may have a problem with blood clots (thrombosis). Because these platelets do not work well, bleeding is also a common problem.
Tefferi A. Myeloproliferative disorders: Essential thrombocythemia and primary myelofibrosis. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier;2007:chap 177.