Many people feel cold, numbness and pins and needles in the lower extremities, when they should be alert to the possibility of ischemic diseases of the lower extremities. The main diseases that cause arterial ischemia in the lower extremities are atherosclerotic occlusive disease, thrombo-occlusive vasculitis, and diabetes combined with neuropathy and peripheral vascular disease. In the early stage, the main manifestations are coldness, numbness and pins and needles in the affected limbs, and marked thickening and pallor of the toe tips and toenails. The next step is difficulty walking. Patients usually feel numbness and swelling pain in the affected limb after walking for less than 100 meters, and limping occurs, so they must stop and rest for a while before continuing to walk. As the disease progresses further, pain appears on top of the above-mentioned symptoms, which gradually worsen. Patients have pain when walking and resting, and the more quiet the night, the more intense the pain. In the late stage, the main manifestation is the blackening and necrosis of the end parts of the toes, outer ankles and heels, and on the basis of necrosis, infection occurs and ulceration is formed. Patients have difficulty sleeping at night and suffer from pain. In addition to improving the blood supply to the lower extremity through medication or surgery, lumbar sympathetic nerve block/destruction is a good treatment for lower extremity ischemic pain and diabetic lower extremity pain. Lumbar sympathetic block/destruction is performed by puncturing a needle under CT guidance to the lumbar paravertebral sympathetic nerve and injecting a destructive drug such as local anesthetic or anhydrous alcohol. After lumbar sympathetic nerve block/destruction, most of the ischemic pain in the lower extremities will be significantly relieved and the blood supply to the lower extremities will be further improved. The advantage is that it is less invasive, safe and effective, and for patients who recur after one injection, another injection is still effective. Lumbar sympathetic nerve block/destruction can also be used to treat the following conditions: nocturnal disease, herpes zoster and postherpetic pain, pain caused by reperfusion after ischemic treatment of the lower extremity; renal colic; complex regional pain syndrome; refractory genitourinary pain; residual limb pain; phantom limb pain; frostbite; hyperhidrosis; erythematous limb pain; hand and foot cyanosis; trench foot, etc.