Glycosylated hemoglobin is a test to check the average blood glucose level in the past 8-12 weeks. Because glycosylated hemoglobin is affected by many factors such as the test method, the presence of anemia and hemoglobin abnormalities and other hematologic diseases, and age, it cannot be used as a basis for confirming a diagnosis of diabetes at this time. In addition, glycosylated hemoglobin cannot reflect the instantaneous blood glucose level and the whole blood glucose fluctuation, nor can it determine whether hypoglycemia has occurred in the course of treatment. Therefore, patients who have been diagnosed with diabetes cannot use glycosylated hemoglobin testing to replace daily blood glucose monitoring. The glycated hemoglobin of normal people is 3%-6%. If high glycated hemoglobin is found, the glucose tolerance test can be further checked to clarify whether there is elevated blood sugar.