Numbness on both sides of the thigh may be related to the following causes: 1. There may be a lumbar disc herniation. At the onset of lumbar disc herniation, it may cause clinical symptoms such as pain, numbness and weakness on one side of the lower extremity by radiation. If numbness occurs on both sides of the thigh, it often suggests that the lumbar disc protrusion is higher and the compression is heavier. 2, there may be central nerve lesions. The symptoms may occur if the spinal canal is occupied, resulting in compression of the spinal cord, or if there is a brain infarction or other disease. 3, there may be complications of diabetes. If the patient has a high blood sugar level for a long time, it may lead to damage to the nerve endings of the peripheral nerves, which then manifests as numbness of the skin sensation, and sometimes the patient often feels numbness in the lower limbs first.