The high incidence of complications from diabetes, the destruction of tissues and organs, and its disabling and lethal nature are serious hazards that also place a heavy economic burden on countries. 11.6% of the world’s health care costs were spent on diabetes prevention and treatment in 2010, and the World Health Organization estimates that China’s economic losses due to diabetes and related cardiovascular diseases amounted to $557.7 billion between 2005 and 2015. The dangers of diabetes are like the tip of an iceberg, and what we see may only be the tip of the iceberg. Studies have shown that 30-40% of patients will develop at least one complication 10 years after the onset of diabetes. 1, acute complications of diabetes: diabetic ketoacid, is the most common acute complication. It occurs mostly in type 1 patients. In severe cases, there will be impaired consciousness until coma; diabetic non-ketotic coma, is a serious acute complication of diabetes. It occurs mostly in elderly type 2 patients. The disease is serious and the mortality rate is high; lactic acidosis, the incidence is not high, but the morbidity and mortality rate is high. 2, chronic complications of diabetes: microvascular complications include diabetic retinopathy, diabetic nephropathy. Macrovascular complications include cardiovascular lesions (coronary artery disease, myocardial infarction), cerebrovascular lesions (cerebral infarction, cerebral hemorrhage). Diabetic neuropathy, diabetic foot. There are many factors that affect the development of diabetes, including the duration of diabetes, the level of blood sugar control, genetic susceptibility, hypertension, smoking, hyperlipidemia, obesity and lack of exercise, etc. 3. An important and easily ignored hazard of diabetes is hypoglycemia, which occurs when blood sugar is below 3.0 mmol/L. The triggering factors of hypoglycemia are worthy of our attention, such as over-injection of insulin or overdose of hypoglycemic drugs, increased exercise or physical activity compared with usual, not eating on time or eating less than usual, significant reduction of vector volume without reducing the dosage of hypoglycemic drugs, sudden emotional changes, unstable diabetes, especially type 1 diabetes, excessive alcohol consumption, especially on an empty stomach, etc. Symptoms of hypoglycemia: Typical symptoms include hunger, cold sweat, palpitations, rapid heartbeat, dizziness and headache, weakness or trembling hands. Atypical symptoms include numbness in the mouth and lips, excessive sweating, excessive dreaming at night, irritability or anxiety, and lack of concentration. Severe symptoms include slurred speech, unconsciousness or disorientation, convulsions, and coma. If you have these symptoms, you should be alert to hypoglycemia. The danger of diabetes involves several organs, cerebrovascular, eyes, heart, kidney, nervous system, vascular system, foot. Diabetic retinopathy is currently the leading cause of adult blindness. type 2 diabetics are at high risk for retinopathy. In adults with type 2 diabetes, approximately 20 to 40% develop retinopathy and 8% have severe vision loss. The major risk factors for diabetic retinopathy include the duration of diabetes, poor glycemic control, hypertension, and dyslipidemia. There are 6 stages of diabetic retinopathy, 3 each in the non-proliferative and proliferative forms. Diabetic nephropathy is also a serious microvascular complication of diabetes and is by far the leading cause of renal failure in the world, both east and west. A survey found that the prevalence of diabetic nephropathy is as high as 34.7% in type 2 diabetic patients, and the high cost of hospitalization, dialysis, and kidney transplantation due to diabetic nephropathy places a heavy burden on patients and families, society, and national health care. 5. Diabetic cardiovascular and cerebrovascular complications refer to the vascular disease caused by diabetes involving the heart and brain vessels, resulting in the accelerated development of cardiovascular and cerebrovascular atherosclerotic lesions, mainly manifested as coronary heart disease, stroke and so on. About 80% of diabetic patients eventually die from cardiovascular and cerebrovascular complications, seriously endangering patients’ lives and health. There are many risk factors for diabetic cardiovascular and cerebrovascular disease, starting with poor overall glycemic control, the main measure of which is elevated hemoglobin. In addition, they include high blood glucose fluctuations and abnormally high postprandial blood glucose. Secondly, in addition to blood sugar, obesity, hypertension, abnormal lipid metabolism and insulin resistance can promote the formation of atherosclerosis, thus leading to the emergence of cardiovascular and cerebrovascular complications. 6, diabetic neuropathy is related to long-term hyperglycemia and microangiopathy. In addition, about 1/5 of diabetic patients already have neuropathy before the diagnosis of diabetes, especially symmetrical peripheral sensory neuropathy is common. The prevalence increases with the duration of diabetes. The prevalence of neuropathy is higher in patients with diabetes who smoke, are over 40 years of age, and have poor glycemic control. Prevention and treatment of diabetic peripheral neuropathy: strict control of blood glucose. Adopt healthy lifestyle habits, stop smoking and limit alcohol consumption. Regular screenings are performed once a year for DPN, and for patients with a long course of diabetes or a combination of microvascular complications such as fundopathy and nephropathy, they should be reviewed every 3-6 months. 7, diabetic foot, commonly known as “rotten feet”, is mainly associated with diabetic lower limb distal nerve abnormalities and varying degrees of peripheral vascular disease, foot infection, ulceration and/or deep tissue destruction is one of the common and very serious chronic complications of diabetes, is one of the most terrible complications of diabetes. Diabetic foot ulcers and gangrene are a significant cause of disability and death in people with diabetes and are the number one cause of nontraumatic amputations in many countries. After seeing the photos of diabetic foot necrosis and amputation, it is very scary and disgusting, I believe there will be many people can not help but look down at their feet. Diabetes is serious enough to lose your toes, and the key is that if you can’t control the progression of the disease, the only way to end up with an amputation. In order to avoid this situation, we must protect our feet. Prevent this complication from happening! Control of blood sugar is the key to preventing and controlling diabetic foot research has found that a 1% decrease in glycosylated hemoglobin reduces the risk of diabetic foot by 43%. 8, risk factors for diabetic foot include: previous history of foot ulcers, peripheral neuropathy and autonomic neuropathy. Foot numbness, decreased or absent sensation of touch or pain, foot fever, absence of skin sweating, muscle atrophy, diarrhea, constipation, and tachycardia. Ischemic vascular lesions. Exercise-induced gastrocnemius pain or cold feet, peripheral vasculopathy. Cold feet, loss of dorsalis pedis artery pulsation, foot deformity. such as eagle’s foot, thickening of the skin at pressure points, other chronic complications of diabetes mellitus. Severe renal pathology, especially renal failure as well as severe loss of vision or blindness, inappropriate footwear, personal factors. Poor socioeconomic conditions, elderly people living alone, lack of knowledge about diabetes, and those who cannot perform effective foot protection. Among the most important risk factors for diabetic foot ulcers are neuropathy, foot deformity and repeated stress effects (trauma), while important factors related to non-healing of diabetic foot wounds are the depth of the wound, infection and the presence of ischemia. This makes regular self-examination and hospital visits particularly important. Early and comprehensive awareness of the dangers of diabetes lays the foundation for a better quality of life in the future for diabetics.