Platelet elevation is the number of platelets in peripheral blood exceeding 400×10*9/L. There are various causes of platelet elevation: if platelets are mildly elevated, the most common causes are infections, neoplastic diseases, and platelet elevation due to hemolysis, and generally the elevated platelet count will gradually decrease after the causative factors are removed. In addition, if the platelet count is severely increased, such as more than 1000×10*9/L, it is commonly found in various myeloproliferative diseases, the most common being primary thrombocytosis, as well as chronic granulocytic leukemia, early myelofibrosis, and true erythrocytosis, etc. In these myeloproliferative diseases, abnormally increased blood cells occur due to disorderly proliferation of hematopoietic stem cells and uncontrolled apoptosis. Abnormally high platelets can cause serious consequences, such as the formation of blood clots and triggering bleeding, and require prompt treatment.