Glycoprotein, or glycated hemoglobin, has normal values and is considered diabetic if the glucose value is higher than the diagnostic criteria, but not diabetic if it is lower than the diagnostic criteria. Glycated hemoglobin reflects the overall control of blood glucose in the last 2-3 months, and cannot reflect instantaneous blood glucose or monitor the occurrence of hypoglycemia in the past, but has a correlation with the degree and duration of blood glucose elevation. Therefore, it is often used as a monitoring indicator of recent glycemic control in diabetic patients. Therefore, normal glycosylated hemoglobin can only indicate better glycemic control in the last 2-3 months. According to China’s diagnostic criteria for diabetes mellitus, diabetes mellitus can be diagnosed when fasting blood glucose exceeds 7.0 mmol/L, or random blood glucose exceeds 11.1 mmol/L, or 2-hour postprandial blood glucose exceeds 11.1 mmol/L, and is combined with symptoms related to diabetes mellitus. Therefore, when the blood glucose value exceeds the above criteria, combined with diabetes symptoms can be diagnosed as diabetes mellitus. If the blood glucose is elevated but does not exceed the above criteria, diabetes mellitus cannot be diagnosed, and it is recommended to monitor the blood glucose on non-same day. It is recommended that diabetic patients monitor fasting blood glucose as well as 2-hour postprandial blood glucose, and if there is any discomfort, they should consult a doctor in time for treatment under the guidance of a doctor.