Whether postprandial glucose 5.7mmol/L is normal or not is mainly judged by the 2h postprandial glucose, which is more meaningful in clinical practice. The range of postprandial 2h blood sugar is 4.4-7.8mmol/L. When the postprandial blood sugar >11.1mmol/L, the blood sugar is not normal. Specific judgments should also be made according to different groups of people: 1. General population: If normal people have postprandial blood sugar of 5.7mmol/L, it belongs to the normal state. If the normal person’s postprandial 2h blood sugar is >7.8mmol/L, it belongs to abnormal situation. If the 2h postprandial blood sugar > 11.1mmol/L indicates the existence of diabetes, so there is no need to worry too much about the emergence of diabetes; 2. Diabetic patients: ordinary young diabetic patients can be regarded as normal if their postprandial blood sugar is 5.7mmol/L. But elderly diabetic patients with postprandial blood glucose 5.7mmol/L are on the low side and are prone to hypoglycemia. If the patient eats less or exercises more, it will easily lead to hypoglycemia. For elderly patients who are older and have underlying diseases, it is not recommended to control postprandial blood sugar below 6.5mmol/L, but preferably 7.0-8.0mmol/L to minimize the episodes of hypoglycemia. In the case of elderly patients, the 2h postprandial blood glucose value can be relaxed even more. Patients with mobility problems, sometimes blood glucose between 9.0-10.0mmol/L are considered normal. Therefore, the normal range of postprandial blood glucose is mainly flexible according to the patient’s specific situation.