Hypoglycemia is a frequent symptom in diabetic patients, and certain hypoglycemic drugs such as insulin and insulin promoters can increase the risk of hypoglycemia in patients. Hypoglycemic episodes may lead to cardiovascular accidents, myocardial infarction, arrhythmias, myocardial ischemia and abnormal function of the autonomic nervous system, so preventing hypoglycemia is an important issue for diabetics to be aware of. First, look at the manifestations and dangers of hypoglycemia. Generally, hypoglycemia can be diagnosed when blood sugar is lower than 2.8 mmol/l. Clinically, hypoglycemia is prone to recurrence, and in serious cases, coma can occur, which can sometimes be life-threatening. The incidence of hypoglycemia in type 2 diabetes is lower than that in type 1 diabetes. The symptoms of hypoglycemia are mainly due to the lack of glucose in neurons. When blood glucose drops to 2.8~3.0mmol/l, insulin secretion is inhibited, glucagon secretion increases, and sympathetic excitation symptoms appear, which are manifested as sweating, trembling, palpitation, nervousness, anxiety, hunger, weakness, pale face, accelerated heart rate, cold limbs and mildly elevated systolic blood pressure. When blood glucose drops to 2.5~2.8 mmol/l, the cerebral cortex is inhibited, followed by the subcortical centers and finally involving the medulla oblongata. Initially, the symptoms are mental inattention, slow thinking and speech, dizziness, drowsiness, blurred vision, unsteady gait, and psychotic symptoms such as hallucinations, agitation, irritability, and strange behavior. When the subcortical layer is inhibited, restlessness and even compulsive convulsions may occur. If hypoglycemia continues to be uncorrected, it is often not easy to reverse or even die. If a patient has symptoms of hypoglycemia, the following treatment is recommended: 1. Diabetic patients receiving glucose-lowering treatment: When the blood glucose concentration drops suddenly or is lower than 3.9mmol/l, measures should be taken to adjust the treatment plan to prevent the possibility of hypoglycemia. The defense of diabetic patients against severe hypoglycemia is to be able to perceive hypoglycemia by themselves at the early stage of blood glucose drop and to eat carbohydrates that can be absorbed quickly immediately. 2.For patients with recurrent hypoglycemia: Various risk factors triggering hypoglycemia should be considered. For patients who have no perceived hypoglycemia, the goal of blood sugar control should be relaxed to avoid the occurrence of hypoglycemia again. 3.Treatment method of hypoglycemia: For most asymptomatic hypoglycemia or mild or moderate symptomatic hypoglycemia, it can be treated by patients themselves. Take 15~20g of glucose orally, or sugar-containing juice, candy, snack, or meal, and the symptoms are usually relieved within 15~20 minutes. In insulin-induced hypoglycemia, the time of blood glucose elevation after oral glucose varies according to the duration of insulin potency maintenance. Shortly after the elevation of blood glucose level, if long-acting or medium-acting insulin is used, more snacks or meals should be eaten and blood glucose should be monitored continuously. When patients with hypoglycemia are unable to take carbohydrates orally, they must be treated by the parenteral route, eating as early as possible when the patient is able to eat safely, and monitoring blood glucose continuously. In terms of treatment, attention should be paid to reducing the risk of hypoglycemia occurrence. For the group prone to hypoglycemia, medications with less risk of hypoglycemia occurrence are recommended. In addition, for patients treated with insulin, the basic + intensive treatment plan is recommended. Then, how should we pay attention to prevent the occurrence of hypoglycemia in general? There are two main points, one is to pay attention to individualization of blood glucose control, and the other is to conduct self-monitoring of blood glucose. Good glycemic control plays an important role in preventing diabetic complications, and the lowest glycosylated hemoglobin is recommended as the goal of glycemic control, which is usually controlled below 7.0%. However, for patients with a history of diabetes >15 years, a history of perceived hypoglycemia with severe co-morbidities such as hepatic or renal insufficiency or large fluctuations in blood glucose throughout the day with recurrent hypoglycemia, glycosylated hemoglobin can be controlled at 7.0%-9.0%. In addition, it is recommended that all diabetic patients perform self-monitoring of blood glucose, and strict monitoring of blood glucose helps to detect the occurrence of hypoglycemia. Blood glucose needs to be measured at any time if hypoglycemia manifests, and if unexplained fasting hyperglycemia or nocturnal hypoglycemia occurs, nighttime blood glucose should be monitored, and continuous ambulatory blood glucose monitoring is recommended if necessary. In addition, various known risk factors for hypoglycemia, such as the timing and amount of meals and extra meals, the arrangement of exercise and the effect of alcohol, should be considered to adjust the treatment plan so that the blood glucose does not fall below 4 mmol/l.