Patients with leg pain who have cold, purple or black skin do not have a direct problem with the nerves, but first have a vascular problem. Initially, the symptoms may be mild, just low skin temperature of the foot or numbness, but as the disease progresses, it slowly appears that after walking a certain distance, you feel soreness and pain in the calf and have to stop and rest for a few minutes, but after a few minutes you can walk again, but the symptoms return after walking the same distance. You should come to the hospital as soon as possible. The pathogenesis of lower extremity atherosclerosis occlusive disease: many patients with atherosclerosis occlusive disease have hyperlipidemia and disorders of lipid metabolism are closely related to the occurrence and development of this disease. In addition, atherosclerotic occlusive disease occurs more often in diabetic patients than in those without diabetes, and makes atherosclerosis occur early and to a severe degree. There is a relationship between smoking and the occurrence and development of atherosclerosis occlusion. Treatment of vascular pain in the lower extremities: 1. conservative treatment: traditional drug therapy mainly dilates arteries with poor efficacy; 2. peripheral vascular interventional techniques, such as: a contrast examination b vascular stenting c umbrella d: revascularization and balloon dilation; 3. cervical, thoracic and lumbar sympathetic nerve block and destruction: its effect is equal to indirect vasodilation; 4. untreatable vascular pain in the lower extremities is referred directly to pain treatment. Benefits of early intervention: early treatment and higher success rate of revascularization.