High fasting blood glucose with normal glycosylated hemoglobin may be caused by physiological factors such as staying up late, stress, or impaired glucose tolerance or diabetes; different causes can be treated by lifestyle changes and hypoglycemic drugs. 1. Physiological factors: Physiological factors such as staying up late, irregular work and rest, eating too much at night, and excessive mental stress may cause high fasting blood glucose with normal glycosylated hemoglobin. High fasting blood glucose can be improved through lifestyle changes, such as regular exercise, regular work and rest, not staying up late, avoiding sugary foods at night, and relaxing appropriately. 2. Impaired glucose tolerance: a state between normal and diabetes, there will also be high fasting blood sugar phenomenon, can be adjusted through diet, reduce the intake of high-sugar foods such as rice, chocolate, etc., and at the same time can be combined with exercise to control blood glucose, temporarily do not need drug treatment. 3. diabetes: fasting blood sugar is high for a long time, greater than 7.0mmol / L, even if the glycated hemoglobin is normal, may also be suffering from diabetes, can be improved through the above lifestyle, appropriate exercise and other ways of controlling blood glucose, such as blood glucose control is not good, but also comply with the doctor’s instructions to take metformin, glibenclamide, insulin and other drugs for hypoglycemic treatment. Glycated hemoglobin normal fasting blood sugar high should go to the hospital in a timely manner, under the guidance of the doctor to carry out regular treatment, to avoid further development of the condition.