Numbness in the left buttock and leg may be caused by a herniated lumbar disc, and similar symptoms may be caused by stroke and hemiplegia. Most of the lumbar disc herniation is due to degenerative changes in the vertebrae, which will compress the adjacent nerve roots, causing symptoms of ischemia and hypoxia in the lower limbs, leading to nerve damage, and also causing similar symptoms of numbness. Patients suffering from long-term hyperlipidemia or hypertension, coupled with the decline in their own immunity, hemiplegia will occur after external stimuli, affecting the stability of the nerve cells in the peripheral circulatory endings, can cause local nerve disorders, resulting in damage to the nerves, causing the symptoms of numbness. Prolonged compression of local muscles, such as holding a position for a long time without moving, can cause similar symptoms.