Patients with primary thrombocythemia have a slow course and most patients are asymptomatic for a long time, but the most important symptoms of this disease are bleeding and thrombosis, which are also the main causes of death in patients at a later stage. Some patients are seen for elevated platelets or splenomegaly on physical examination. Patients are also seen for bleeding tendencies, the most common bleeding being gum bleeding, nasal bleeding, skin purpura, and gastrointestinal bleeding. Blood clots are most often seen in limb ischemia and manifest as Raynaud’s phenomenon. Other visceral arteries and veins may also develop thrombosis. Mild to moderate splenomegaly is present in 50 to 80 percent of ET patients, and about half of patients have mild hepatomegaly and no lymph node enlargement. The survival of patients with primary thrombocytosis is comparable to that of normal subjects, and the goal of treatment is to reduce the platelet count in order to control and prevent bleeding, thrombosis, and embolism. How is all thrombocythemia treated? 1, myelosuppressive drugs (1) hydroxyurea: the occurrence of rapid action, discontinuation of the secondary effect is short, often preferred; according to the rate of platelet decline to adjust the dose, pay attention to the adverse effects of leukocyte reduction, to improve and platelets down to normal, the maintenance or intermittent treatment with small doses to prevent relapse. (2) Leucovorin: the effect occurs slowly, after discontinuation of the drug can have subsequent effects, is also commonly used, safe and effective drugs. It is advisable to use a small dose and take it orally in several doses. (3) Other: cyclophosphamide can also be used in divided oral doses, for more than 1 month; high trichostatin 2-4mg intravenous infusion, once a day, for 1 week, rest 1 to 2 weeks and then repeat. 2, interferon: in recent years α interferon and γ interferon used to treat idiopathic thrombocythemia, the dose of 3-5MU / d, after 4-6 weeks to 2-3 times a week. It can control the number of peripheral platelets and improve platelet function by inhibiting the proliferative activity of bone marrow megakaryocytes, but it has less effect on the life span of platelets. 3, platelet isolation: platelets are prone to thrombosis when they are too high, and this method can be used to rapidly reduce the number of platelets and improve the symptoms. After separation, the number of platelets is reduced and then maintained with drugs to keep the platelets at a low level. 4.Combination of Chinese and Western medicine treatment. 5.Other anticoagulant drugs: Heparin or bicoumarins are available for the treatment of thrombotic complications.