Glucose tolerance generally refers to glucose tolerance test. Patients undergoing oral glucose tolerance test are required to mix 75 grams of anhydrous glucose into 250-300 milliliters of water. Oral glucose tolerance test is a kind of sugar load test, which generally requires a certain amount of anhydrous glucose to be taken orally, i.e., 75 grams of anhydrous glucose to be mixed into 250~300 ml of water, and blood glucose will be drawn before and 30 minutes, one hour, two hours and three hours after taking the test respectively to observe the patient’s blood glucose. It should be noted that the test needs to be 8 hours before the test can not take in any calories, sugar water need to drink within 5 minutes, and in the testing process, can not drink coffee, strong tea and other beverages. In case of abnormal blood glucose values, it is recommended to go to the hospital.