Thigh root swelling after walking, the possible causes are strenuous exercise, lower extremity vascular circulation disorders, lumbar intervertebral disc herniation, lumbar spinal stenosis and so on. 1. Strenuous exercise: after walking, due to excessive fatigue, excessive exercise, thigh root swelling symptoms will occur. 2. Lower extremity vascular circulation disorders: after walking, there are lower extremity vascular circulation disorders, resulting in poor blood flow, and there will be a feeling of thigh root numbness and swelling. 3. Herniated lumbar disc: after walking, the lumbar intervertebral disc compresses the local nerve root, which leads to the aggravation of the symptoms in the process of walking, resulting in thigh root pain, numbness and swelling, weakness and other symptoms. 4. Lumbar spinal stenosis: due to congenital spinal canal underdevelopment or acquired factors such as spinal trauma, degenerative changes in the spine, inflammation, etc., resulting in lumbar spinal stenosis, the patient in the thigh root after brisk walking, soreness, numbness, distension, or pain in the thigh root symptoms. Thigh root numbness and swelling after walking may also have other reasons, it is recommended to go to the regular hospital in time to improve the relevant examination, clear the cause of the disease, under the guidance of the doctor to carry out targeted treatment or treatment.