If a leg is numb, and suddenly appear: First, consider cerebrovascular disease, seen in the radiation coronary area or thalamus small ischemic foci and trace hemorrhage, the patient can appear leg numbness, after the head CT or nuclear magnetic examination can be found. Second, if the legs are numb clinically can also be seen in the lumbar spine diseases, such as lumbar disc herniation or lumbar spinal stenosis, the patient can be due to compression of the sciatic nerve and leg numbness, can be a line of numbness, give the patient to check the CT or MRI of the cervical disc. Third, if the numbness of both lower limbs, clinically can also be seen in peripheral neuropathy, especially long-term heavy drinking or diabetic patients, due to peripheral nerve damage patients appear leg numbness, if necessary, you can check the electromyography.