Limb ulcers are broken or ulcerated limbs that occur on the human body. The vast majority of patients think that they have to see a dermatologist or surgeon when they have an extremity ulcer, but they do not know that many extremity ulcers, especially those that are difficult to heal and close, are mostly caused by peripheral vascular diseases. Peripheral vascular diseases that cause limb ulcers can be divided into two main categories. Arterial disease occurs in the terminal foot of the lower extremity, with severe pain and ulcers characterized by irregular edges at first and later jagged, with grayish-white granulation tissue covering the bottom. It does not bleed easily when touched. These diseases are often preceded by ischemic manifestations of the limbs before they break in the early stages: such as coldness, coldness, soreness, numbness, and pain in the lower limbs, which is especially pronounced at night. The main arterial diseases causing limb ulcers are: atherosclerotic occlusive disease, thrombo-occlusive vasculitis, diabetic vasculopathy, etc. Since most of the ulcers caused by arterial diseases are ischemic ulcers, their treatment should focus on improving the ischemic state of the limbs. Venous disease is characterized by shallow and irregular ulcers, large in size, and bleeding easily when touched, which tend to occur in the distal 1/3 of the lower leg above the inner and outer ankle. It does not usually cause pain. The main venous diseases causing limb ulcers are varicose veins of the lower extremities, deep venous reflux disorders, and sequelae of acute deep vein thrombosis. Since most of the ulcers caused by venous diseases are stasis ulcers, their treatment should focus on improving the circulatory status of the limbs and promoting blood return. Limb ulcers caused by peripheral vascular diseases often bring great inconvenience to people’s work and life because of their chronic, difficult-to-heal and recurring characteristics. In particular, ulcers caused by arterial diseases can eventually lead to serious consequences of amputation or finger (toe) amputation if they are not controlled in a timely and effective manner. For limb ulcers, especially chronic ulcers that do not heal for a long time don’t forget to see a vascular surgeon to get early and proper treatment.