Fasting blood glucose 6.6mmol/L is high and abnormal for normal people; it is within the target range and normal for diabetic patients. 1. The normal value of fasting blood glucose for normal people is between 3.9~6.1mmol/L, so fasting blood glucose 6.6mmol/L is high, and it is recommended to consult a professional physician for a clear diagnosis. 2. For patients who have been diagnosed with diabetes in the past, the general fasting blood glucose should be controlled between 4.4~7.0mmol/L, so the fasting blood glucose of 6.6mmol/L can reach the control target, and can continue the current treatment program. Patients with high fasting blood glucose need to pay attention to the usual diet of small meals, low-fat and low-sugar, eat more vegetables, eat less sugary fruits, in addition, the patient can be appropriate exercise, such as jogging, playing Tai Chi and so on. Specific treatment programs need to consult a doctor.