Patients only feel coldness in the skin temperature of the affected limb, or mild numbness, and are easily fatigued after activity. Atherosclerotic plaque forms on the inner wall of arterial vessels, and as the plaque increases and the lumen narrows, the patency of the pipeline is affected, and the blood flow to the lower limbs is reduced, and when the narrowing reaches a certain level or even completely blocked, the blood flow supplying the lower limbs cannot meet the needs, and the symptoms of lower limb ischemia appear. The clinical symptoms of patients with atherosclerosis depend mainly on the speed and degree of development of limb ischemia. No matter how extensive the occlusive lesion is, as long as the lesion of arterial blockage develops slowly, the collateral circulation can be effectively established, the branch blood flow increases accordingly, and the blood supply is compensated, so that the degree of tissue suffering from ischemia and hypoxia can be moderated, and there are even no obvious clinical symptoms of ischemia. If the lesion develops faster, the establishment of collateral circulation is incomplete, and compensation is limited, the patient may have obvious symptoms such as intermittent claudication and limb pain. According to the severity of the patient’s symptoms, the clinical manifestations are generally divided into 4 stages according to Fontaine staging. Stage 1, mild complaint stage Patients only feel reduced skin temperature and coldness of the affected limb, or mild numbness, easy fatigue after activity, and the limb end is prone to tinea pedis infection which is not easily controlled. Phase 2, intermittent claudication When the patient is walking, due to ischemia and hypoxia, the more common part is the muscle of the lower leg that produces spasm, pain and fatigue, and the patient must stop walking and rest for a moment before the symptoms are relieved and the activity can be continued. If you walk a distance again, the symptoms recur. Intermittent claudication of the lower leg is the most common symptom of ischemic lesions of the lower extremity. Stage 3, resting pain stage When the lesion develops further and the establishment of lateral branch circulation is seriously insufficient, the affected limb is in a rather severe ischemic state, and pain, numbness and abnormal sensation are felt even at rest. The pain is usually predominant at the extremity. Stage 4, tissue necrosis stage Mainly, the lesion continues to develop to the occlusive stage, with very limited collateral circulation and symptoms of nutritional disorders. Prior to the development of ulceration or gangrene, the skin temperature decreases and the color is dark purple. Early gangrene and ulcers tend to occur on the toes, and as the lesion progresses, the infection and gangrene may gradually progress upward to the foot, ankle, or lower leg, and in severe cases, systemic toxicity may occur.