A blood glucose of 6.8 mmol/L is high if it is fasting, but normal if it is 6.8 mmol/L two hours after a meal or 6.8 mmol/L measured at random. If the fasting blood sugar 6.8mmol / L, belong to the fasting blood sugar regulation is impaired, for the pre-diabetes. Normal fasting blood glucose is 3.9-6.1mmol/L, between 6.1-7.0mmol/L belongs to pre-diabetes, that is, impaired regulation of fasting blood glucose. If the blood glucose is ≥11.1 mmol/L two hours after the meal, the diagnosis of diabetes mellitus can also be confirmed. If the two-hour postprandial blood glucose is <7.8 mmol/L, then impaired fasting glucose regulation is present. If the blood glucose two hours after the meal is between 7.8 and 11.1 mmol/L, it belongs to the stage of glucose tolerance abnormality, at this time, as long as the diet and exercise control, generally can make the blood glucose standard. If the blood glucose still cannot reach the standard after diet and exercise, we should choose suitable hypoglycemic drugs under the guidance of endocrinologists.