If the fasting blood glucose is 6.55 mmol/L, it is high, and if the two-hour postprandial blood glucose is 6.55 mmol/L, it is within the normal range; elevated fasting blood glucose may be caused by stress, or it may be caused by impaired fasting blood glucose and other reasons. Stress or impaired fasting blood glucose is possible to normalize blood glucose levels, diabetes is difficult to cure. 1. Stress: Acute infection, trauma and other stressful situations may cause a transient increase in blood glucose, after active treatment to eliminate the source of stress, blood glucose is likely to return to normal. 2. Impaired fasting glucose regulation: In such cases, it is usually recommended to make dietary adjustments, such as controlling total calorie intake, quitting smoking and limiting alcohol consumption, as well as appropriate physical exercise, it is possible to normalize blood glucose, but it is also possible to develop diabetes mellitus further. 3. Diabetes mellitus: Once diagnosed, diabetes mellitus usually requires lifelong treatment, and can only be lowered by oral glucose-lowering drugs such as gliclazide, acarbose or insulin injections, but it is difficult to cure. Fasting blood glucose 6.55mmol/L is recommended to go to the hospital; two hours after meal blood glucose 6.55mmol/L is normal, no special treatment.