Hypoglycemia is a serious complication that can occur during the treatment of diabetes. It is common in the elderly, in patients with reduced renal function and in those with severe microvascular and macrovascular complications, and is a problem that should be given special attention in the process of achieving blood glucose control goals. A single severe hypoglycemia can cause serious effects on the heart, kidney, brain and other organs, and even cancel out the benefits gained by the patient in long-term blood glucose control. A blood glucose level of ≤3.9 mmmol/l in diabetic patients falls into the category of hypoglycemia. Many things can cause hypoglycemia: such as the use of sulfonylurea or non-sulfonylurea insulin stimulants, too many insulin injections, eating too little, missing meals, low-carbohydrate diets, exercising too much, drinking alcohol on an empty stomach, etc. Patients with diabetes should perform blood glucose self-testing on time. Start with a small dose when applying insulin or insulin promoter in life and treatment, gradually increase the dose and adjust the dose carefully. Patients who do not eat on time or eat too little should eat regularly and quantitatively, and if the amount of meals decreases the dose of medication should be reduced accordingly, and should be prepared in advance when there is a possibility of missing meals. If the amount of exercise increases, additional carbohydrate intake should be added before exercise. In order to effectively prevent the occurrence of hypoglycemia, the daily diet and activity should be kept relatively stable, and if physical exertion activities are to be carried out, attention should be paid to eating more food containing carbohydrates. Carry candy, cookies and other blood sugar-raising foods with you at all times. Insulin or oral hypoglycemic drugs should be injected and taken regularly and in the right amount. If once you have symptoms such as rapid heartbeat, dizziness, sweating, eyes glazed over and trembling all over, it may be a symptom of hypoglycemia, please drink sugar water, or sweet drinks, consume bread, buns, etc. immediately. If the symptoms are not relieved or you cannot find the reason for the blood sugar drop too low, please make a record of it and go to the hospital in time to ask the doctor to judge whether the dosage of insulin or medication needs to be reduced.