Numbness of the legs is not necessarily a precursor of disease, it may be a physiological factor or an early symptom or typical symptom of disease, such as lumbar lesions, sciatic neuropathy, cerebrovascular lesions, arterial occlusive vasculitis of the lower extremities, diabetic peripheral neuropathy. 1. Physiological factors: sedentary, stilt legs may lead to lower extremity blood circulation disorders, resulting in leg numbness, appropriate exercise will relieve the symptoms. 2. Lumbar lesions: lumbar spinal stenosis, lumbar spinal tumor, lumbar spondylolisthesis, lumbar intervertebral disc herniation may lead to sciatic nerve root compression, inducing numbness of legs and feet. 3. Sciatic nerve lesions: pyriformis syndrome, sacroiliitis can lead to sciatic nerve injury, inflammatory reaction, usually induces numbness of legs and feet. 4. Cerebrovascular lesions: cerebral infarction, cerebral hemorrhage can lead to persistent numbness in the legs. 5. Arterial occlusive vasculitis of the lower limbs: vascular lesions of the lower limbs will affect the normal blood circulation, and patients will have numbness in the legs. 6. Diabetic peripheral neuropathy: due to long-term high blood sugar stimulation, caused by metabolic disorders, caused by peripheral nerve damage will lead to numbness of the legs, and later there will be a decrease in reflexes and other manifestations. The causes of leg numbness are more complex, it is recommended to go to the hospital for examination and treatment if the phenomenon of leg numbness persists.