Tags: Disease.
Thrombocytosis (or thrombocythemia) is the presence of high platelet counts in the blood and can be either primary (also termed essential and caused by a myeloproliferative disease) or reactive (also termed secondary). Although often symptomless (particularly when it is a secondary reaction) it can predispose to thrombosis in some patients.In a healthy individual a normal platelet count ranges from 150000 and 450000 per mm³ (or microlitre) (150–450 x 109/L).