The 4-hour postprandial blood glucose, generally can be regarded as random blood glucose, 6.8mmol / L for diabetic patients usually belong to the glycemic control standard, for undiagnosed diabetes mellitus people belong to the normal, but the 4-hour postprandial blood glucose is not a commonly used clinical indicators, it is recommended to improve the fasting, postprandial blood glucose 2 hours testing. For people with diabetes, the glycemic control goal is generally in the fasting blood glucose 4.4mmol / L ~ 7.0mmol / L, non-fasting blood glucose does not exceed 10.0mmol / L. 4 hours after the meal blood glucose 6.8mmol / L belongs to the normal situation, the blood glucose control is basically good, belongs to the range of the control target, the specific glycemic control goal needs to be formulated according to the individual situation. For people with undiagnosed diabetes, random blood glucose is normal not more than 7.8mmol/L, so 4 hours after meal blood glucose 6.8mmol/L is normal, it is recommended to improve the fasting, 2 hours after meal blood glucose test. It is recommended to consult a doctor in time for blood glucose abnormalities.