According to the latest guidelines, high glycosylated hemoglobin (≥6.5%) is also diagnostic of diabetes mellitus despite normal blood glucose. Glycated hemoglobin represents the level of glycemic control in the last 2-3 months. The normal reference value is 4.0% to 6.0%, with slight variations in different laboratory markers. Significantly higher values indicate poor glycemic control in the last 2-3 months, and diabetic patients are required to keep their glycated hemoglobin below 7.0%. Recent guidelines suggest that a glycosylated hemoglobin of ≥6.5% is diagnostic of diabetes. Blood glucose represents an immediate blood glucose level and can only indicate the level of blood glucose at the time of testing. Patients on regular glucose-lowering medications may also have blood glucose in the normal range at the time of testing, so a normal blood glucose level cannot rule out diabetes. High glycosylated hemoglobin is recommended to go to the hospital in time, under the guidance of the doctor to clarify the diagnosis and standardized treatment.