High platelets are a warning against diseases such as essential thrombocythemia and chronic granulocytic leukemia. However, high platelets may also be caused by physiological factors, such as profuse sweating, diarrhea and so on. 1. Pathological factors: high platelets need to be vigilant for myeloproliferative diseases, such as primary thrombocythemia, chronic granulocytic leukemia, primary myelofibrosis, myelodysplastic syndrome and so on. It may also be caused by bacterial, viral and other pathogenic infections in the body, resulting in high platelets. 2. Physiological factors: high platelets are not necessarily caused by disease factors, but may also be caused by physiological factors, such as sweating, diarrhea, etc., leading to dehydration, blood concentration, triggering the phenomenon of physiological platelet increase. When the body condition returns to normal, the platelet value will also recover. It is recommended that patients with high platelets consult a doctor to determine whether they are suffering from the disease. If they are ill, they should follow the doctor’s instructions to treat the cause of the illness.