High blood sugar before going to bed and normal fasting in the morning may be caused by dietary factors, or may be caused by insufficient dose of medication; the former caused by the need to adjust dietary habits, the latter caused by adjusting the dose of medication. 1. Dietary factors: eating late-night snacks before going to bed or eating some overly greasy food at dinner can cause elevated blood glucose before going to bed, but normal fasting blood glucose in the morning; in such cases, you should avoid eating before going to bed, and keep a low-sugar, low-fat and low-salt diet at dinner. 2. Insufficient dosage of medication: Insufficient dosage of medication can cause pre-bedtime blood glucose elevation, but fasting blood glucose is normal; in such cases, you can increase the dosage of medication under the guidance of a doctor to reduce the concentration of pre-bedtime blood glucose. If you have high blood glucose before bedtime and normal fasting blood glucose in the morning, it is recommended to go to the hospital after excluding dietary factors.