Fever does not usually affect glycated hemoglobin. Glycated hemoglobin is the product of combining hemoglobin from red blood cells with sugars from the serum. It can help diagnose diabetes and reflects the average blood sugar or glycemic control over the last 2 to 3 months. Its normal range is 4% to 6%. Any factor that alters the life span of red blood cells such as hemolytic anemia, chronic malaria, aplastic anemia, massive blood loss, or blood transfusions can lead to inaccurate results. For normal people, if the glycosylated hemoglobin exceeds 6.5%, endocrinology consultation is recommended to further refine the glucose tolerance test to clarify the diagnosis. For diabetic patients, if the glycosylated hemoglobin exceeds 7%, it indicates that the recent blood sugar control is not good, and it is recommended to further monitor the fasting and two-hour postprandial blood glucose, and adjust the glucose-lowering program under the guidance of endocrine specialists in a timely manner.