Low blood sugar does not necessarily lead to diabetes, but many diabetic patients in the early stages, will have pre-meal hypoglycemia, so it is necessary to clarify whether the patient’s low blood sugar occurs before or after a meal, and whether it is fasting or before the next meal. If a patient frequently has low fasting blood glucose, you need to be alert to the presence of conditions such as insulinoma. If the patient often has low blood sugar before the next meal, it is recommended that the patient should go to the endocrinology department of the hospital in a timely manner and improve fasting blood sugar and 2h postprandial blood sugar, and if necessary, improve the OGTT test of 75g anhydrous glucose to clarify the situation of glucose tolerance, and if necessary, improve glycated hemoglobin to help clarify the diagnosis of diabetes or prediabetes.