Blood glucose 15.5mmol/L, both fasting blood glucose and postprandial blood glucose, has exceeded the diagnostic criteria as well as the control range of diabetes mellitus, which belongs to a more serious situation. The normal fasting whole blood glucose range is 3.9~6.1mmol/L, and the two-hour postprandial glucose range should be less than 7.8mmol/L. Therefore, whether it is fasting glucose or postprandial glucose, the blood glucose of 15.5mmol/L is abnormal and belongs to the more serious one. For blood sugar 15.5mmol / L, should cause the patient’s attention, clear the cause of increased blood sugar, whether it is short-term strenuous exercise, high sugar diet, emotional excitement and other physiological factors, or diabetes and other pathological causes, clear causes, standardized treatment, to avoid delaying the condition. It is recommended that patients with blood glucose of 15.5mmol/L should consult a doctor for standardized treatment under the guidance of a doctor, and should not abuse drugs privately to avoid aggravating their condition.