I. Pain Pain is mainly caused by insufficient arterial blood supply. 1, intermittent claudication – a typical symptom of chronic limb ischemia Intermittent claudication, also known as motor pain, occurs mostly in the calf gastrocnemius area, characterized by weakness, pressure, numbness, dull pain or spasmodic sharp pain in the affected limb after the patient walks a certain distance, which is relieved after a period of rest, but continued walking can produce the same symptoms. The shorter the distance of continuous walking, the more serious the condition. The pain caused by insufficient blood supply is aggravated by elevating the patient, and the pain is significantly aggravated at night, so the patient with serious condition sits on his knees all night, moans and cannot sleep flat; 2. Skin changes (a) Skin color changes The color of normal skin: light red, lustrous and elastic. Lower limb deep venous insufficiency secondary to lower leg traffic venous insufficiency: distal calf with skin dystrophic changes, such as skin thinning, desquamation, toenail degeneration, hair thinning, pigmentation, eczema, etc.; chronic arterial insufficiency: pale limb skin with reduced skin temperature. Lymphangitis or thrombotic superficial phlebitis: red lines on the skin of the limb. (ii) Ulcers Both arterial insufficiency and venous reflux disorders have chronic ulcers: arterial ulcers and venous ulcers 1. Arterial ulcers: Prevalent at the extremities, with clear borders and deep ulcers with black necrotic tissue. Pain is obvious, often relieved at rest or when the limb is lowered. The limb temperature is low, and the dorsalis pedis artery pulsation is weakened or disappears. 2.Venous ulcer: It occurs in the lower 1/3 of the lower limb of the inner ankle or anterior tibia, with uneven edges, red granulation tissue on the wound surface and little necrotic tissue. The pain is mild and often relieved when the limb is elevated. The limb temperature is normal, and the dorsalis pedis artery pulsation is normal. Third, abnormal sensation or paralysis In mild cases, there is an ant walking sensation on the skin; in severe cases, the patient is paralyzed and the deep and superficial sensation is dulled or disappeared, and in severe cases, the limb is paralyzed and unable to move.