Primary thrombocythemia

Alternative names:

essential thrombocythemia; essential thrombocytosis; hemorrhagic thrombocythemia

Definition:

A condition of overproduction of the platelet cells without a recognizable cause.

Causes, incidence, and risk factors:

The cause of the disease is unknown, and although the platelets are primarily affected, the red blood cells and white blood cells are also involved. The disease has similarities to polycythemia vera, chronic myelogenous leukemia, and myelofibrosis. Usually it affects people who are over 50 years old. Bleeding can occur from the gastrointestinal, respiratory, urinary tract, or skin. The formation of blood clots called thrombosis may coincide with bleeding episodes and may even cause strokes in some people. Risk factors are unknown. The incidence is 1 out of 100,000 people.