6.65mmol/L is mildly elevated if it is fasting blood glucose, which needs diet or exercise treatment; if it is postprandial or random blood glucose, no treatment is needed. Fasting blood sugar normal reference range is 3.9-6.1mmol/L, fasting blood sugar 6.65mmol/L, belongs to a mildly high, may be impaired fasting blood sugar, need to improve the glucose tolerance test and other tests to further clarify the diet or exercise treatment, if necessary, under the guidance of the doctor to use medication. Normal 2-hour postprandial blood glucose is less than 7.8mmol/L, random normal blood glucose is less than 11.1mmol/L. If the blood glucose measured after meal or any moment is 6.65mmol/L, and there is no other discomforts, there is no need to worry too much. When abnormal blood glucose occurs, it is recommended to consult a doctor in time, follow the doctor’s instructions for further examination, clarify the cause with the help of the doctor, and carry out targeted treatment or therapy.