The clinical diagnosis of diabetes tests done when the vein is usually measured fasting blood glucose. When the venous fasting blood glucose <5.0mmol / L, can be ruled out diabetes; When the venous fasting blood glucose> 7.0mmol / L and there are clinical symptoms, can be diagnosed with diabetes; and when venous fasting blood glucose in the 5.5 ~ 7.0mmol / L, and between suspected diabetes, you should make further oral glucose tolerance test --- OGTT. OGTT test is an oral glucose challenge test to understand the body's blood sugar after the consumption of glucose regulation. Through the OGTT test, can be early detection of abnormal glucose metabolism, early diagnosis of diabetes.How to test it? 1. To do three days before the OGTT test should not be controlled diet, daily dietary carbohydrate content should not be less than 150 grams, and to maintain normal activities. 2. Affecting the test drugs (high or low blood sugar caused by the drug) should be disabled. 3. Before the test, the patient should be 10 to 14 hours without eating. 4. Test day the morning after fasting venous blood obtained within 5 minutes into the 300 ml drink containing 75 grams of glucose syrup, drinking sugar water 30 minutes, 1 hour, 2 hours each venous blood sampling time, and Urine fluid do urine qualitative test. Throughout the trial not to smoke, drink coffee, tea or eating, should be quietly sitting in a chair. Results of the pilot to determine it? 1. When the venous fasting blood glucose <6.1mmol / L, OGTT two-hour blood glucose <7.8mmol / L, shows the body's blood sugar after eating ability to regulate glucose to normal, as normal glucose tolerance. 2. When the venous fasting plasma glucose ? 7.0mmol / L or a two-hour OGTT glucose ? 11.1mmol / L, urine +~++++, shows the body after eating glucose treatment significantly reduced the ability to have reached the diagnostic criteria of diabetes mellitus. 3. When the venous fasting blood glucose <7.0mmol / L, and the two-hour OGTT plasma glucose between 7.8 ~ 11.1mmol / L, means the body's ability to regulate glucose slight decline has reached the diagnostic criteria for impaired glucose tolerance. 4. When the venous fasting blood glucose between 6.1 ~ 7.0mmol / L between, and the two-hour OGTT plasma glucose ? 7.8mmol / L, shows the body after the consumption of glucose ability to regulate blood sugar is still good, but slightly decreased ability to regulate blood sugar fasting, has reached the diagnostic criteria for impaired fasting glucose.