A glycosylated hemoglobin of 5.9% is usually normal. The normal standard value of glycosylated hemoglobin is 4.0% to 6.0%, and diabetic patients are usually controlled below 7.0%. Glycated hemoglobin reflects the average blood glucose value in the last 3 months, and the normal standard value is 4.0% to 6.0%. Glycated hemoglobin 5.9%, indicating that the average value of blood glucose in the past 3 months is normal, but also need to improve the fasting blood glucose, postprandial blood glucose and other tests, a comprehensive assessment. For diabetic patients, the goal of glycemic control is generally in the fasting blood glucose 4.4mmol / L ~ 7.0mmol / L, non-fasting blood glucose does not exceed 10.0mmol / L, glycated hemoglobin below 7.0%, but also according to the individual situation indicators of glycemic control goals. In addition, the results of glycosylated hemoglobin are not absolute and may be affected by different factors such as the test method, the presence or absence of blood system disorders, and age, so it cannot be used as a substitute for daily blood glucose monitoring. It is recommended to seek prompt medical attention and improve the examination if the glycated hemoglobin is abnormal.