There is usually no normal standard value for bedtime blood glucose, which can be determined on an individual basis and should not be too low to prevent hypoglycemic reactions. In general, blood glucose peaks about 2 hours after a meal, and blood glucose can return to normal level in 3 to 5 hours, and bedtime blood glucose should be no less than fasting blood glucose. However, bedtime blood glucose can be affected by a variety of factors, such as meal time, the amount of food eaten, the food eaten, the amount of exercise after meals, etc. Therefore, bedtime blood glucose is not used as an indicator for the diagnosis of diabetes mellitus, and there is generally no reference to the normal value. The main clinical significance of bedtime blood glucose is to monitor the blood glucose situation of diabetic patients and to adjust glucose-lowering drugs and insulin appropriately before bedtime, so as to avoid nocturnal hypoglycemia and rebound to cause blood glucose elevation in the early morning. If blood glucose is low before bedtime, glucose-lowering drugs need to be reduced appropriately or meals added before bedtime, while when blood glucose is high before bedtime, control needs to be strengthened. Changes in blood glucose should be closely monitored to facilitate the doctor to adjust the treatment program.