Numbness in the perineum may be caused by lumbar spine disease, trauma, nerve injurious disease and other reasons, which need to be analyzed specifically. 1. Lumbar spine disease: if there are lumbar disc herniation, spinal stenosis and other diseases, it will compress the nerves and make the innervated place feel numb. 2. Trauma: If the perineum is injured by straddling injuries or other conditions that cause perineal injuries, the perineal nerves will be damaged, which may also cause numbness in the perineum. 3. Nerve damage disease: if there is a nerve infection, diabetes and other conditions, so that the nerve is damaged, can also lead to local sensory disorders, numbness in the perineum. Numbness of the perineum may also be caused by other reasons, which need to seek medical treatment in time and under the guidance of the doctor.