Glucose tolerance is the abbreviation of oral glucose tolerance use, is a glucose load test, mainly used for the diagnosis of diabetes mellitus, how to smooth the examination is as follows: Within 3 days before the test, the daily carbohydrate intake is not less than 150g, and you should have a normal diet. Discontinue drugs that may affect the glucose tolerance test before the test, such as birth control pills, diuretics, phenytoin sodium, and the situation allows you to stop the drug for 3 to 7 days. It is important to note 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 during the test, avoid smoking, drinking alcohol, coffee and strong tea, and do not strenuous exercise. Before taking the glucose tolerance test, you need to know whether you have any underlying diseases. If you have fever, infection or trauma, it is not recommended to take the glucose tolerance test and you need to wait until your body recovers to normal, and you should consult with your medical professional for details.