1, a variety of triggers: triggers are the fuse for the occurrence of diabetic foot. Common triggers include diabetic maculopathy, arterial thrombosis, burns, frostbite, corns, calluses and trauma, etc. 2, infection: infection is often a secondary lesion of neuropathy and vascular lesions. Local ischemia is prone to infection, often caused by very small skin wounds and more serious infections, which in turn can aggravate diabetes. Frequently infected bacteria include Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa and anaerobic bacilli. 3, vascular lesions ischemia: diabetic lower extremity vascular lesions are the pathological basis for the occurrence of diabetic foot. Arterial vascular lesions refer to atherosclerosis, with plaque formation in the arterial wall. There are deposits of lipids such as cholesterol in the plaque, which narrow or block the lumen of the blood vessel. Due to atherosclerosis, arterial intima damage and blood vessels become narrow or even occluded, local blood flow is blocked and ischemic necrosis occurs, which leads to the occurrence of this disease. 4, neuropathy: diabetic neuropathy is one of the important causes of diabetic foot. Due to the neuropathy of the lower limbs, the pain, touch and temperature sensation of the foot is weakened or disappeared, and the local resistance is reduced, making it vulnerable to various injuries. Certain traumas, such as the extrusion of ill-fitting shoes, foot calluses, improper handling of corns, friction of sock stitching, and skin trauma, can cause the occurrence of foot infections.