Blood glucose 12.8mmol / L both fasting blood glucose or 2 hours after meal blood glucose is high, may be hyperthyroidism, diabetes, Cushing’s syndrome and other diseases caused by standardized treatment to control the condition is generally not serious, but not standardized treatment may lead to disease progression or complications occur, is more serious. The normal range of fasting blood glucose is 3.9~6.1mmol/L, and the normal range of blood glucose 2 hours after meal should be less than 7.8mmol/L. Therefore, the blood glucose of 12.8mmol/L is on the high side whether it’s fasting blood glucose or 2 hours blood glucose after meal, which may be caused by hyperthyroidism, diabetes mellitus, Cushing’s syndrome and other diseases. Diabetic patients need to be treated by dietary control, appropriate exercise, the use of glucose-lowering drugs such as metformin, to maintain blood glucose stabilization is not considered serious, if the non-standardized treatment of diabetes mellitus induced acute complications or chronic complications such as macrovascular disease, renal lesions is more serious. Patients with hyperthyroidism can follow the doctor’s instructions to use antithyroid drugs, such as methimazole, or iodine 131 radiation therapy, to maintain the level of thyroid hormones within a reasonable range, blood glucose can be restored to the normal level, it is not considered serious; if the non-standardized treatment leads to thyroid crisis, hyperthyroidism heart disease and other serious complications, it is more serious. When blood glucose 12.8mmol/L occurs, it is recommended to go to the hospital in time, under the guidance of the doctor’s judgment, to clarify the cause of the disease and timely treatment, so as not to delay the condition.