Fasting 7.8mmol / L whether need to take drugs can not be generalized, the first need to clarify whether the diabetes, if meet the criteria for diabetes first need to improve lifestyle, dietary adjustments and appropriate exercise. If the blood sugar is still high, then you need to take hypoglycemic drugs. The normal range of fasting blood glucose should be 3.9～6.1mmol/L, fasting blood glucose 7.8mmol/L is higher than normal. At this time, further detailed examination of venous fasting blood glucose, 2 hours after meal blood glucose, glucose tolerance test and glycated hemoglobin should be clarified whether it is diabetes or not. If the diagnostic criteria of diabetes mellitus are met (symptoms of diabetes mellitus, i.e., polydipsia, polyuria, polyphagia, weight loss plus random blood glucose ≥11.1 mmol/L or fasting blood glucose ≥7 mmol/L or glucose tolerance test 2-hour blood glucose ≥11.1 mmol/L), first of all, the blood glucose should be monitored regularly, the lifestyle improved, and the diet adjusted and the appropriate amount of exercise should be used to control the blood glucose. If blood glucose is still high after dietary adjustment and appropriate exercise, it is necessary to use medication under the guidance of a professional endocrinologist, such as metformin, acarbose and other hypoglycemic drugs. When fasting blood glucose 7.8mmol / L should be timely medical treatment under the guidance of a doctor.