Eat sugar is also known as postprandial blood sugar, eat sugar measured blood sugar 8.7 fasting measured 9.49, that is to say, fasting blood sugar is higher than postprandial blood sugar is why, the reason may be dawn phenomenon, insufficient dosage of medication, Sumujie phenomenon, and so on. 1. Dawn phenomenon: It means that blood glucose control is good at night and there is no hypoglycemia, but at dawn, because of the excessive secretion of cortisol, growth hormone and other hormones that have antagonistic effect on insulin, which leads to high fasting blood glucose at dawn, in this kind of situation, you can measure blood glucose several times at night to identify. 2. Insufficient drug dosage: Insufficient insulin or hypoglycemic drugs applied before bedtime cannot effectively reduce fasting blood glucose, leading to the emergence of fasting blood glucose higher than postprandial blood glucose. 3. Sumuje phenomenon: when there is undetected hypoglycemia at night, the body is in a protective mechanism, which will increase the secretion of hormones that antagonize insulin, resulting in rebound hyperglycemia after hypoglycemia. If fasting blood glucose is higher than postprandial blood glucose frequently, you should go to the regular hospital in time and adjust the hypoglycemic drugs under the guidance of the doctor.