If a patient suspects that he or she has diabetes, a glucose tolerance test should be performed at the hospital as follows: Oral glucose (83 grams of glucose powder) tolerance test: [Principle] Under a certain dose of glucose load, if the pancreatic islets are deficient and cannot release sufficient amount of insulin, it can lead to an increase in blood glucose, while the blood glucose of these patients is normal during non-glucose load. OGTT is the main method to detect these patients with reduced glucose tolerance (IGT). ［The total daily caloric intake of the patient should be sufficient to maintain body weight and the carbohydrate content of the diet should not be less than 300 grams on the 3 days before the test. 2. Fasting after dinner 1 day before the trial and fasting overnight. 3.Patients should avoid strenuous exercise, no smoking and no coffee during the test. 4, 1ml of blood was collected from the forearm as a control (0 hour value). 5, Dissolve 83g of glucose powder in 300ml of warm boiled water and drink it within 5 minutes. 6.Start from the first sip of sugar water to record the time, and draw blood at 0.5 hours or 1 hour or 2 hours to measure blood glucose and insulin concentration respectively. [Normal reference value] Fasting blood glucose <6.1mmol/L (110mg/dl), 1 hour <9.0mmol/L (160mg/dl) 2 hours <7.8mmol/L (140mg/dl) Consult your doctor after getting the results.