Numbness in the legs is mainly due to two reasons: the first is caused by a herniated lumbar disc that compresses the nerve roots. The second one is caused by the prolonged sitting posture, which can cause pressure on the blood vessels in the legs, resulting in poor blood flow. It is recommended that a lumbar spine CT and lower limb arterial ultrasound be taken at the local hospital in time to make a clear diagnosis. To prevent these conditions, the main thing is to avoid prolonged sitting, standing, walking or straining. Normally, attention should be paid to life regulation, oral nerve-nourishing drugs and exercise of the lumbar back muscles can be taken. If the symptoms are not relieved, surgery can be performed.