The normal value of postprandial glucose is in the range of 4.4-7.8 mmol/L. If it is less than 4.4 mmol/L, it is called hypoglycemia. Common causes of hypoglycemia are early diabetes, poor appetite recently, i.e. poor absorption in the gastrointestinal tract, gastrointestinal surgery, islet cell tumor. If the postprandial blood sugar is greater than 7.8mmol/L, there are two cases, as follows: 1. abnormal glucose tolerance: postprandial blood sugar between 7.8-11.1mmol/L is called abnormal glucose tolerance, this situation does not need to take hypoglycemic drugs, only need to maintain blood sugar below 7.8mmol/L through diet plus exercise; 2. diabetes: if the postprandial blood sugar is greater than 11.1mmol /L, it can be diagnosed as diabetes. After the diagnosis of diabetes, we should improve blood routine, liver function and glycosylated hemoglobin, and decide to use glucose-lowering drugs according to liver function, kidney function and blood routine.