High platelet should go to the hospital for a clear diagnosis and removal of the cause, such as anti-infection, chemotherapy, etc., and anticoagulation is needed if necessary. Causes of high platelets include: bacterial or viral infections; non-infectious factors, such as malignant tumors, trauma, stress, etc.; hematologic disorders, such as myelodysplastic syndromes, idiopathic thrombocytosis, and so on. Treatment includes treatment according to the cause and treatment according to the symptoms. 1. Treatment according to the cause: if caused by bacterial or viral infection, anti-viral and anti-infection treatment is needed; if caused by trauma or malignant tumor, surgery or anti-tumor treatment can be taken; if caused by hematologic diseases, such as primary myelofibrosis and myelodysplastic syndromes, hematopoietic stem cell transplantation or oral hydroxyurea chemotherapy can be used. 2. Treatment according to symptoms: lowering platelets and preventing complications such as thrombosis. Increased platelets but less than 1000×10^9/L, the risk of thrombosis is high, oral aspirin anticoagulation is recommended. If the patient’s platelet count is excessively or persistently high, it is recommended to visit the hospital in time to clarify the cause of the disease and target treatment. Drugs should be used under the guidance of a doctor.