Numbness in the arms and legs of the elderly may be caused by the following reasons: first, head diseases, when there is a tumor in the head or cerebral infarction, cerebral hemorrhage, there can be symptoms of numbness in one arm and leg, then the relevant CT and MRI examination of the head should be carried out for early diagnosis and treatment; second, cervical spondylosis, when the cervical spondylosis is spinal cervical spondylosis, there can be numbness and weakness of the limbs. When cervical spondylosis is a spinal cord type of cervical spondylosis, numbness and weakness of the extremities can occur, and walking can be accompanied by walking disorders, a sense of stepping on cotton, and a feeling of unstable direction, and in this case, X-ray, CT and MRI of the cervical spine should be performed for early diagnosis and treatment, and if necessary, surgery is also required. The diagnosis should be made by physical examination and electromyography to exclude other diseases.