Higher blood sugar in the morning than at bedtime may be abnormal or normal. Specifically as follows: 1. abnormal: (1) Sumuje phenomenon: blood glucose is not high before going to bed, but hypoglycemia occurs at night, causing rebound hyperglycemia in the morning, and there may be a morning fasting blood glucose higher than the blood glucose before going to bed. (2) Dawn phenomenon: pre-bedtime blood glucose is not high, nighttime blood glucose is normal, but at dawn the body secretes a lot of hormones that are antagonistic to insulin, and these hormones lead to elevated blood glucose and cause morning fasting blood glucose higher than pre-bedtime blood glucose. 2. Normal: The normal range of morning fasting blood glucose is 3.9~6.1mmol/l, and the normal range of pre-bedtime blood glucose is less than 11.1mmol/l. If the pre-bedtime blood glucose is not high, the morning blood glucose is a little bit higher than the pre-bedtime blood glucose, but the morning blood glucose and pre-bedtime blood glucose are both within the range of the reference value, which is a normal phenomenon. When abnormal blood glucose levels are detected, it is recommended to seek prompt medical attention.