There are many reasons why one leg is weak, and the common ones are lumbar intervertebral disc herniation, pyriformis syndrome and cerebral infarction.
1. Lumbar disc herniation: due to the degeneration of lumbar intervertebral discs, the fibrous annulus ruptures partially or completely, and the nucleus pulposus protrudes or prolapses, irritating or compressing the nerve root and cauda equina, causing a syndrome. It often manifests as lumbar pain, weakness and numbness of one or both lower limbs.
2. Piriformis syndrome: because the sciatic nerve is compressed in the region of the piriformis muscle, it mainly manifests as pain in the buttocks and radiating pain in the lower limbs, and when the pain is obvious, painful claudication may occur.
3. Cerebral infarction: limited ischemic necrosis or softening of brain tissue due to ischemia and hypoxia of the brain, paroxysmal sensory and motor disorders may occur before the attack, such as weakness of one leg, dizziness, and so on.
There may be other reasons such as vascular lesions in the lower limbs, etc. It is recommended to go to the hospital in time, complete the examination to clarify the cause of the disease, and actively standardize the treatment.