The severity of platelets 669 x 10^9/L, i.e., platelets higher than normal, is related to the cause of thrombocytosis, individual differences, and cannot be generalized. Elevated platelet count may be related to certain diseases, such as infection, primary thrombocythemia, etc. Generally, platelets will return to normal after controlling the primary disease. If primary thrombocythemia is treated with drugs such as hydroxyurea and aspirin. The platelet elevation caused by certain malignant diseases is relatively serious, such as chronic granulocytic leukemia, malignant tumors, myelofibrosis in the early stage. In addition, the blood is in a state of high coagulation when the platelet is increased, which can lead to thrombosis, and if the thrombus embolizes the heart, brain, lungs and other important organs, it may lead to serious adverse consequences. For people with underlying diseases and poor physical condition, it may lead to more serious consequences. When platelets are elevated, it is recommended to consult a doctor in time for relevant examinations to clarify the cause of the disease and standardize the treatment under the doctor’s guidance so as to avoid delaying the condition.