Fasting blood glucose 7.8mmol / L is not normal, if accompanied by symptoms of diabetes, by the regular hospital review can be diagnosed with diabetes. For diabetic patients, fasting blood glucose 7.8mmol / L generally belongs to the sugar control does not meet the standard. Fasting blood glucose 3.9 ~ 6.0mmol / L is normal, 6.1 ~ 6.9mmol / L for impaired fasting glucose regulation, ≥ 7.0mmol / L at the same time diabetes symptoms can be diagnosed as diabetes. For diabetic patients, the goal of glycemic control is generally in the fasting blood glucose 4.4mmol / L ~ 7.0mmol / L. So fasting blood glucose 7.8mmol / L is not normal. Fasting blood sugar 7.8mmol / L should go to the hospital, improve the 2 hours after meal blood sugar, glucose tolerance test and glycated hemoglobin and other related examinations, to clarify the presence of diabetes or adjust the treatment program.