Anyone older than 50 years old with the following symptoms may have lower extremity atherosclerosis occlusive disease and should promptly consult vascular surgery. 1. Weakness, coldness, chilliness and intermittent claudication in both lower limbs. Male patients often show the inability to erect the penis. Arterial pulsation below the femoral artery is often diminished or absent. The manifestations such as decreased skin temperature and pale skin may occur. If left untreated, the condition will progressively worsen and eventually gangrene of the limb will develop. Suggested lesion site: occlusion at the bifurcation of the abdominal aorta is likely. 2. Intermittent claudication causes pain mainly in the buttocks, inner thighs and lumbar pain, weakened or absent femoral artery pulsation, reduced foot temperature, slow toenail growth, and reduced foot sweat. Suggest lesion site: iliac artery occlusion. 3. Insufficient blood supply to the calf muscles, intermittent claudication with painful points in the calf, cold and chilly feet, dry skin, weakened or absent arterial pulsation below the N artery. Suggest lesion site: femoral N artery occlusion. 4. Intermittent claudication, low foot temperature, and loss of pulsation of the dorsalis pedis artery or posterior tibial artery. Suggest lesion site: occlusion of the anterior and posterior tibial arteries. 5.Pale and bruised toes, pain at night and inability to sleep quietly indicate severe ischemia of the lesion and possible necrosis and ulceration of the foot. It belongs to the third stage of arteriosclerosis occlusive disease ischemia, and should be hospitalized immediately. 6.Foot coldness, severe pain, limb necrosis and ulceration belong to stage IV ischemia of atherosclerosis occlusive disease, which is difficult to treat and has a high rate of amputation.