For the diagnosis of diabetes, in addition to the fasting blood glucose standard, there is also the standard of blood glucose 2 hours after meals, any one of which can diagnose diabetes by reaching the diagnostic standard of diabetes, when diagnosing diabetes, the determination of blood glucose 2 hours after meals is not the daily diet but a certain amount of glucose, not the determination of rapid blood glucose but the determination of blood glucose by taking venous blood, so as to more accurately diagnose the existence of diabetes. In this way, a more accurate diagnosis of diabetes can be made. This is when we need to use the glucose tolerance test (OGTT), and we will get to know it comprehensively below. I. What is the glucose tolerance test (OGTT)? Glucose tolerance test, also known as glucose tolerance test, refers to the body’s ability to tolerate glucose intake, and is a laboratory test to diagnose diabetes. In simple terms, it is the change in blood sugar over a certain period of time after taking a certain amount of glucose by mouth. After a normal person takes a certain amount of glucose, the blood glucose concentration temporarily increases, but within 2 hours the blood glucose concentration can return to the normal fasting level again. If the glucose metabolism is abnormal due to endocrine dysfunction and other factors, the blood glucose concentration may rise sharply after consuming a certain amount of glucose, and it cannot return to the original concentration level within a short time, which is called abnormal glucose tolerance. Therefore, the glucose tolerance test is mainly used to diagnose whether the blood sugar is normal after the test person’s sugar load. Second, what kind of people need to do glucose tolerance test? 1.Suspected of having diabetes, but the fasting blood glucose result alone cannot determine the person. 2.When fasting blood glucose is higher than the normal range but does not meet the diagnostic criteria for diabetes. 3.Diabetes mellitus has been diagnosed and a comprehensive understanding of the patient’s peak glucose secretion, insulin secretion function, C-peptide, etc. is needed. 4.The glucose in urine shows positive but not high blood sugar. 5.Pregnant women who are suspected of having gestational diabetes mellitus. 6.Patients who have family history of diabetes and have normal fasting blood sugar but have symptoms such as weakness and thirst. 3.How to do the glucose tolerance test? 1.Stop using all drugs that may raise blood sugar, such as hormonal drugs, diuretics, contraceptives, tricyclic antidepressants, etc. 1 week before the test. 2, 3 days before the test, daily carbohydrate intake is controlled at 250-300g, to have normal physical activity, excessive dieting will cause artificial abnormalities in glucose tolerance. 2, the night before the test fasting 8-14 hours, that is to say, to the start of the test to fast for more than 8 hours. 3, before the test and during the test to prohibit any food, wine, coffee, tea, can be appropriate to drink water, to maintain emotional stability, avoid strenuous exercise. 4. Fasting blood should be drawn before 8:00 a.m. and 300 ml of water containing 75 g of glucose should be drunk within 5 minutes. children should take 1.75 g of sugar per kg of body weight. 5. Blood was drawn and blood glucose values were measured 1 hour, 2 hours and 3 hours after drinking sugar water.