A normal glucose tolerance is usually not diabetes. Diabetes mellitus is a metabolic disease characterized by chronic hyperglycemia caused by multiple etiologies. Clinical diagnosis of diabetes mellitus requires clinical symptoms plus a random blood glucose ≥11.1 mmol/L or a fasting blood glucose ≥7.0 mmol/L or an oral glucose tolerance test (OGTT) 2-hour blood glucose ≥11.1 mmol/L. Abnormal glucose tolerance is the pre-diabetic stage, at this time OGTT 2-hour blood glucose in 7.8~11.1mmol/L, indicating that at this time the body sugar metabolism is abnormal, and should be taken seriously. If the glucose tolerance is normal, it means that the body’s glucose metabolism level is still in the normal range at the time of this test, but the test may sometimes have a certain degree of error, and if there are symptoms of diabetes mellitus (polydipsia, polyphagia, polyuria, and unexplained weight loss), in order to make a definitive diagnosis, the OGTT test can be performed again. If the glucose tolerance test is abnormal, it is recommended to consult a doctor in time and follow the doctor’s instructions for treatment.