Leg swelling may be related to leg muscle strain, vascular factors, lumbar spine disease, etc. The specific analysis is as follows: 1. Leg muscle strain: such as marathon, soccer and other strenuous exercise, may make the leg muscle injury, local aseptic inflammation, causing the symptoms of leg swelling. 2. Vascular factors: such as vasculitis, vascular occlusion, atherosclerosis and other factors, may cause muscle ischemia, causing leg swelling, pain and other symptoms. 3. Lumbar spine diseases: such as lumbar disc herniation, lumbar spinal stenosis, compression of the sciatic nerve, etc., which may cause the symptoms of leg swelling and pain, and may be accompanied by numbness of the legs, intermittent claudication and other symptoms. It is recommended to go to the hospital in time to improve the relevant examination after the leg swelling and difficult to find out the cause of the treatment under the guidance of the doctor.