Whether or not it is normal to have a high 2-hour postprandial blood glucose that goes back down at 3 hours needs to be determined by the patient’s blood glucose profile. If the 2-hour postprandial blood glucose is high and the blood glucose is between 7.8 and 11.1 mmol per liter, impaired glucose tolerance is considered. If impaired glucose tolerance should be intervened through diet control and appropriate exercise. If the blood glucose reaches 11.1 mmol per liter or above, and the typical clinical symptoms of “three more and one less” (i.e., more drinking, more eating, more urination, and weight loss) appear, or the 2-hour postprandial blood glucose is still higher than 11.1 mmol per liter, it is considered that diabetes mellitus may be present. Diabetes can also be diagnosed by fasting blood glucose and random blood glucose. If it is clear that you have diabetes you should follow your doctor’s instructions to adjust your blood glucose with glucose-lowering medication and control your diet with appropriate daily exercise to bring your blood glucose up to standard. If you suspect that your blood sugar is increased or you have diabetes, you should go to the endocrinology department of the hospital.