In normal individuals, the 2-hour postprandial glucose range may vary under different physiologic conditions. The 2-hour postprandial blood glucose is an important time point of interest in the diagnosis and management of diabetes. For the majority of the general population, the normal 2-hour postprandial plasma glucose range is 4.7-7.8 mmol/L, and 7.8-11.1 mmol/L is considered abnormal glucose tolerance. Clinically, diabetes mellitus can be diagnosed if the postprandial blood glucose is >11.1mmol/L and there are obvious diabetes mellitus symptoms, such as weight loss, easy to eat and starve, nocturnal enuresis, thirst and drinking, and blurred vision in both eyes. While the 2-hour postprandial blood glucose level of pregnant women should be controlled at 4.4-6.7mmol/L, gestational diabetes can be diagnosed if the 2-hour postprandial blood glucose > 8.5mmol/L. In addition, postprandial blood glucose is easily affected by the amount of food and meal times, which may lead to some errors in measurement. For patients with high postprandial glucose and suspected diabetes mellitus, it is recommended to further go to the endocrinology department of the hospital for relevant examinations, such as postprandial glucose examination after taking 75 grams of glucose orally.