Old Li just over 60 years old, retired from the position of manager before leisure exercise, every morning and evening walk for sports exercise, but he found that non-stop walking for about half an hour to feel sore and weak left leg, had to stop and rest, rest for a while on the good can also continue to walk. So walking and stopping, old Zhao thought he often sat in the car lack of exercise, and did not care, thinking that later to strengthen the exercise will be better. Who knows that the walking distance is getting shorter and shorter, to the nearby hospital to take a look, and X-ray and CT of the waist, have not found any problems. I just thought it was because I was old and weak and continued to exercise. One night, he suddenly felt severe pain in his left leg and was rushed to the hospital, thinking that it was a sprain from exercise, but the treatment did not improve for a few days, but he saw that the skin of his left foot was blue and dark. Everyone has heard that atherosclerosis can cause coronary heart disease and stroke hemiplegia, but fewer people know that atherosclerosis can affect the feet. The fact is that atherosclerosis can have a significant impact on the feet. The incidence of chronic lower limb arterial ischemia in people over 60 years old is about 20%, and more than 75% of patients with serious cardiovascular disease have peripheral arterial obstruction. Just like water pipes grow scale over time, atherosclerosis is also caused by the deposition of harmful substances on the walls of arteries, making the walls thicken and harden and lose elasticity, resulting in stenosis or even occlusion, reducing or even interrupting the blood supply to the distal end and causing ischemia or even necrosis of the corresponding tissues and organs. Atherosclerosis is the most common vascular lesion in humans and can occur in many locations, causing coronary heart disease and cerebral thrombosis, as well as ischemic necrosis of the lower extremities. Lower extremity atherosclerosis is divided into four stages from mild to severe: the first stage may not have any uncomfortable symptoms, but the arteries can be found to have sclerotic changes by instrumentation. The second stage mainly manifests as pain after exercise, medically known as intermittent claudication, mainly characterized by no symptoms at rest and soreness and weakness of the lower limbs after walking a certain distance, which can be relieved after rest. It is often accompanied by coldness, coldness and thickening and deformation of the toenails. In the third stage, the pain appears even in a quiet state and intensifies at night, often making it difficult to sleep because of the pain. In the fourth stage, there is ulceration and necrosis of the foot, and patients have difficulty sleeping at night due to severe pain, moaning and crying, and exchanging tears. There are many patients who think of suicide because they can hardly bear the pain, and some patients have to amputate their limbs and are left with lifelong disabilities. If detected in the first and second stages and treated correctly, patients can avoid the great pain of limb ulceration and necrosis, and early detection and treatment is the key to prevent serious consequences.