The presence or absence of diabetic complications or their severity plays a decisive role in the life and prognosis of diabetic patients. Nowadays, many diabetic patients only pay attention to hypoglycemic treatment and are completely unaware of the complications that may result from diabetes. As a result, there are many complications such as significant loss of vision, blindness, proteinuria, uremia, foot gangrene, amputation, cerebrovascular lesions, coronary heart disease, and heart attack. At least one complication occurs in 30% to 60% of patients 10 years after the onset of diabetes. Our study showed that 60% and 36% of the diabetic and prediabetic population in the Shanghai community had chronic complications, respectively. The prevalence of neuropathy in diabetes can reach 61.8%, retinopathy 37.5%, and diabetic nephropathy 34.7%, and 5-10% of patients deteriorate to end-stage renal disease 20 years after the disease, requiring hemodialysis and kidney transplantation, or face death. In addition, the risk of cardiovascular disease in diabetic patients is 2 to 4 times higher than in the general population, and the age of onset is earlier. Due to vascular and neurological lesions in diabetic patients, foot ulcers and consequent amputations often result. Chronic complications of diabetes are related to chronic hyperglycemia and metabolic disorders, with insidious onset and gradual development. Although diabetes complications are very dangerous, they can be effectively prevented and treated, and the quality of life and life expectancy of diabetic patients can be the same as normal people. How to prevent and treat diabetic complications First of all, early detection and treatment is the most important measure to prevent and treat diabetic complications. Therefore, for the diabetic population, screening for chronic complications of diabetes is carried out for early detection of chronic complications of diabetes. Patients with diabetes should have their liver and kidney functions and blood lipids measured at least annually, and those with abnormalities should be checked every six months or three months. Patients with hypertension should have their blood pressure monitored at least once a week, and patients with type 2 diabetes should have their fundus checked annually with dilated pupils from the onset of the disease. The 24-hour urine albumin quantification or urine albumin-to-creatinine ratio should be checked every six months and repeated every three months for abnormalities. Peripheral neuropathy lesions and lower limb vascular lesions should be checked regularly every year, such as electromyography, Doppler ultrasonography, blood flow measurement, and brachial artery to dorsalis pedis artery blood pressure ratio. In addition, ECG and carotid ultrasound should be done regularly for early detection of coronary artery disease and atherosclerosis. Second, to control blood glucose for a long time This is very important, not only to control fasting blood glucose, but also to control postprandial blood glucose, and should make the glycosylated hemoglobin index control below 7%, so as to minimize the occurrence of diabetic complications. Thirdly, blood pressure and lipids should be controlled. Hypertension and hyperlipidemia are important factors that cause vascular damage, and diabetes complications are all related to vascular damage. Diabetes is often accompanied by hypertension and hyperlipidemia. Diabetic patients with hypertension should have their blood pressure controlled below 130 /80mmHg, and patients with proteinuria and renal impairment should have their blood pressure below 125/75mmHg. Blood cholesterol, triglycerides and low-density lipoprotein are related to diabetic complications and should be controlled in the normal range for as long as possible. Obesity should be prevented and smoking should be reduced. Several clinical studies have confirmed that, regardless of type 1 or type 2 diabetes, when treating diabetes, in addition to strict control of blood glucose, strict control of related risk factors such as blood pressure, blood lipids, and body weight at the same time can reduce the incidence of many microvascular and macrovascular complications of diabetes, such as stroke, heart failure, and fundoplication, by 30% to 60%, and significantly reduce diabetes-related deaths.