Clinically, the bedtime blood sugar of normal population is the basal blood sugar under non-fasting, fluctuating at 4.4-6.1mmol/L as normal blood sugar level. For diabetic patients, the requirement range of bedtime blood glucose in the process of glucose-lowering treatment is different according to the age of onset, and the requirements are mainly seen in the following cases: 1. Elderly diabetic patients: the bedtime blood glucose should not be controlled too low to avoid the occurrence of nighttime hypoglycemia, and the bedtime blood glucose is generally required to be controlled around 7.8mmol/L, and should not be lower than 7.8mmol/L. 2. Young diabetic patients : No complications of diabetes can be strictly controlled blood sugar, generally bedtime blood sugar fluctuation between 4.4-6.1mmol/L can be. The monitoring of blood glucose before bedtime in diabetic patients is especially crucial to prevent the occurrence of hypoglycemia at night, and according to different age of onset, attention should be paid to the requirement of individualized blood glucose control.