There are many reasons why this happens: 1. problems with the lumbar spine, if a lumbar disc herniation compresses the nerve roots, it can cause numbness in the feet of the lower limbs, which requires a lumbar spine CT or MRI for clarification. 2. sequelae of cerebral infarction or cerebral hemorrhage, in addition to causing numbness in the legs and feet, can also have symptoms such as limb paralysis, slurred speech, swallowing disorders, cognitive impairment, etc., which can be identified by cranial CT or MRI. 3. 3. Inflammatory or demyelinating lesions of the spinal cord can cause numbness in the feet, weakness, and disorders of urination and defecation, which require spinal MRI and lumbar puncture. 4. Green-Barre syndrome can also cause numbness in the lower extremities, but mostly numbness in the distal part of the feet, which can be combined with weakness of the limbs, which require electromyography and lumbar puncture.