The numbness of legs may be caused by the lesion of lumbar medulla, which may be caused by the compression of lumbar medulla by lumbar disc herniation, or by the compression of intramedullary tumors, and it is necessary to check the lumbar spine MRI in order to make a clear diagnosis. At the same time, lumbar pain may also occur, and in severe cases, weakness of both lower limbs may also occur, and may even cause urinary and fecal disorders, urinary and fecal retention and urinary and fecal incontinence, and should be hospitalized for comprehensive treatment if necessary. It may also be caused by cerebrovascular disease, usually seen in the brain stem lesions, at the same time there may be weakness of the lower limbs, dizziness, total disorders, dysphagia and choking on drinking water, if necessary, check the cranial brain MRI has been clearly diagnosed. The disease is usually seen in middle-aged and elderly people, acute onset, common causes include hypertension, diabetes mellitus and hyperlipidemia, usually after the onset of the need to be hospitalized for comprehensive treatment. It may also be a peripheral neuropathy. The disease is mainly manifested as sensory deficits, most patients start from one side of the lower limbs with symptoms, can gradually involve the opposite lower limbs, and involve both upper limbs, etc., the main nutritional nerve treatment, commonly used drugs are vitamin B12 and methylcobalamin, the diagnosis of the disease is mainly electromyography, which may help in the diagnosis of the disease.