Whether the nighttime blood glucose is normal or not depends on the time of the last meal and the time of blood glucose measurement. Normal people’s fasting blood glucose should be in the range of 3.9-6.1 mmol/l, and 2 hours after meal should be <7.8 mmol/l; diabetic patients' fasting blood glucose should be in the range of 4.4-7.0 mmol/l, and 2 hours after meal should be <10.0 mmol/l. 1. Fasting blood glucose: it means that no food has been eaten for 8 consecutive hours without any calorie intake. At this time, normal people's blood sugar is 3.9-6.1 mmol/l, while diabetic patients' blood sugar should be 4.4-7.0 mmol/l. 2. 2-hour postprandial blood glucose: refers to the blood glucose value measured 2 hours after the meal, normal people's blood glucose does not exceed 7.8 mmol/l, and diabetic patients' blood glucose does not exceed 10.0 mmol/l. 3. For different diabetic people, there are differences in the required blood glucose values. For young diabetic patients, the blood glucose control should be close to normal; for elderly diabetic patients with serious cardiovascular and cerebrovascular diseases, inability to take care of their own life or tendency to hypoglycemia, we should appropriately relax the requirements of blood glucose control. If blood glucose abnormality occurs, it is recommended to go to the hospital in time for treatment under the guidance of the doctor.