The reference range of normal value of platelet count is (100~300)×10⁹/L. The causes of increase are exercise, high temperature, chronic granulocytic leukemia, primary thrombocythemia, acute infections, etc.; the causes of decrease are aplastic anemia, acute myeloid leukemia, thrombocytopenic purpura, etc. The clinical reference range of normal value of platelet count is (100~300)×10⁹/L. Abnormal platelet count is helpful for doctors to diagnose and identify blood system diseases. The reference range of normal value of clinical platelet count is (100~300)×10⁹/L. Platelet count helps doctors to diagnose and identify hematologic diseases, and abnormal indexes can be seen in physiological and pathological causes. 1. Usually, platelet counts exceeding normal values may be due to physiologic reasons such as strenuous exercise and high temperatures. 2. Pathological causes of abnormal index can be seen in chronic granulocytic leukemia, acute infection, acute blood loss, acute hemolysis, myelodysplastic syndrome, aplastic anemia, thrombocytopenic purpura, hypersplenism and other diseases. If the platelet count is abnormal, the patient should undergo further examination to clarify the specific cause of the disease and then cooperate with the doctor for treatment.