Blood glucose is divided into fasting and postprandial, the normal value of fasting is 3.9-6.1mmol/L, and the normal value of postprandial is 3.9-7.8mmol/L. For diabetic patients, the normal values are ≥7mmol/L in fasting and ≥11.1mmol/L in postprandial. Fasting blood glucose between 6.1-7mmol/L is called fasting hyperglycemia, and postprandial blood glucose between 7.8-11.1mmol/L is called abnormal glucose tolerance. A fasting blood glucose of 6.1-7 mmol/L is called fasting hyperglycemia, and a postprandial blood glucose of 7.8-11.1 mmol/L is called abnormal glucose tolerance. For new onset diabetes, it is recommended to keep blood glucose in the normal range, i.e., between 3.9-6.1 mmol/L for fasting and 3.9-7.8 mmol/L for postprandial. Patients with chronic diabetes for more than 10 years are recommended to keep their fasting glucose below 7 mmol/L, postprandial glucose below 10 mmol/L, and glycosylated hemoglobin below 7%. Blood sugar should be controlled differently for different people, but for normal people it should be controlled in the normal range.

The normal value of blood glucose requires that the fasting blood glucose is less than 6.1 mmol/L and the blood glucose two hours after meal is less than 7.8 mmol/L. This is the normal value of blood glucose. Therefore, the diagnosis of diabetes mellitus is based on a fasting blood glucose greater than 7 mmol/L and a blood glucose greater than 11.1 mmol/L two hours after a meal.

Fasting blood glucose between 6.1-7mmol/L and postprandial blood glucose between 7.8-11.1mmol/L is called impaired glucose regulation, and is often referred to as pre-diabetes by the general public in clinical practice. If the control is not good will transition to diabetes, so blood sugar is divided into three cases, normal blood sugar, pre-diabetes and diabetes.

Normal blood sugar fasting 4 to 6.1.