Checking fasting blood glucose at 11:00 a.m. is generally inaccurate, and hypoglycemia may occur, so it is recommended to check blood glucose under the guidance of a doctor. Fasting blood glucose generally refers to the blood glucose value detected by plasma taken before breakfast after overnight fasting (at least 8 to 10 hours without any food, except drinking water), which can reflect the function of pancreatic B-cells, and generally indicates the function of basal insulin secretion, and is the most commonly used indicator for diabetes mellitus. Its reference range is 3.9~6.1mmol/l. Checking blood glucose at 11:00 a.m., when fasting for too long may lead to inaccurate testing and low blood glucose values. Patients who need to test their blood glucose are advised to follow their doctor’s instructions to do so, and to seek prompt medical attention if they find their blood glucose levels abnormal.