Thrombocytosis is defined as the presence of high platelet counts in the blood which can be either primary or reactive. Thrombocytosis can occur in patients with polycythemia vera i.e., in high red blood cell counts which is an additional risk factor for other complications.
Thrombocytosis is a main potential cause for thrombophilia. The extrapolated prevalence for thrombocytosis in Norway was found to be 239,973 for 16,318,199 populations.
In cases of reactive thrombocytosis low dose of aspirin is administered to minimize the risk of thrombocytosis. Extremely high platelet counts in primary thrombocytosis can be treated with hydroxyurea which is an cytoreducing agent or anagrelide.