What is a diabetic foot? Diabetic foot is a foot ulcer, infection and/or deep tissue destruction associated with local nerve abnormalities and peripheral vascular disease in the distal lower extremities that occurs in diabetic patients; it is one of the common chronic complications of diabetes and causes a heavy socioeconomic burden and is difficult to diagnose and treat. What is the epidemiology and risk of diabetic foot? In Western countries, 5-10% of diabetic patients have foot ulcers of varying degrees during their lifetime, 1% of diabetic patients have their limbs amputated, and 85% of diabetic patients have their limbs amputated due to diabetic foot ulcers, making the diabetic foot the number one cause of amputation in many countries. The cost of treating diabetic foot ulcers in developed countries is about $16,000 to $27,000, and the cost of amputation is even higher; the cost of diabetic foot disease accounts for 1/3 of the medical cost of diabetes. In 2004, a survey in China showed that the prevalence of foot disease was 37.6% among 71-80 year olds, 27.4% among 61-70 year olds, 20.2% among 51-60 year olds, 6.6% among 41-50 year olds, 6.2% among 81-90 year olds 6.2%, 30~40 years old 1.8%, >90 years old 0.3%; the average hospitalization day for diabetic foot disease patients is 26 days, and the average medical cost is 15,000 yuan. As the absolute number of diabetic patients in China increases dramatically and the survival period of patients is prolonged, the prevalence of diabetic foot disease and its medical costs are bound to grow rapidly. Recent surveys have shown that diabetic foot ulcers have become the leading cause of chronic ulcers among hospitalized patients in China, increasing from 4.9% in a 1996 survey to 33% in a 2008 survey. The recurrence rate of diabetic foot ulcers is high: 34% at 1 year, 61% at 3 years and 70% at 5 years; the mortality rate of above-knee amputation is high: 10% for amputation, 30% within 1 year, 50% within 3 years and 70% within 5 years after amputation. Through prevention of diabetic foot ulcers, early diagnosis and active management of diabetic foot disease, more than 90% of amputations can be prevented.