Diagnostic criteria for diabetes mellitus:

Normal fasting blood glucose range of 3.15-6.19mmol/L, postprandial blood glucose 2-hour blood glucose <7.8mmol/L, when the fasting blood glucose ≥ 7.0mmol/L, postprandial blood glucose 2 hours ≥ 11.1mmol/L for diabetes mellitus; if the fasting blood glucose in the range of 6.1mmol/L ~ 7.0mmol/L is diabetes. If the fasting blood sugar is between 6.1mmol/L and 7.0mmol/L, then it is called fasting blood sugar impairment. If fasting blood glucose is normal and postprandial blood glucose is 7.8mmol/L to 11.1mmol/L, it is called impaired glucose tolerance. Impaired fasting glucose and impaired glucose tolerance can be seen as a transitional stage from normal to diabetes, but can be reversed to normal with proper treatment. If not treated properly, it progresses to diabetes.

The normal concentration of blood glucose in humans is: fasting venous plasma glucose 3.9-6.0 mmol/L, postprandial venous plasma glucose <7.8 mmol/L.

The normal value of glycosylated hemoglobin is less than 6.5%. Normal value of glycosylated hemoglobin:4.6～6.4.

Criteria for diagnosing diabetes mellitus by glucose tolerance test and steamed bread meal test: diabetes mellitus can be diagnosed by fasting blood glucose ≥7.0mmol/L, 2-hour blood glucose ≥11.1mmol/L, or blood glucose ≥11.1mmol/L at any time.