Thigh and buttock sides acid cold may be related to lumbar intervertebral disc herniation, rheumatoid arthritis, sciatic neuritis and so on. 1. Lumbar disc herniation: refers to lumbar fibrous ring rupture, part of the nucleus pulposus and the ruptured fibrous ring protrudes into the spinal canal, compressing the nerve root causing lumbar pain, sciatica, and also appearing in the legs and buttocks soreness and coldness. 2. Rheumatoid arthritis: It is a systemic autoimmune disease that mainly affects joints and is characterized by chronic, symmetrical, peripheral polyarthritic lesions. The main manifestations are pain, swelling and functional decline of the affected joints. When inflammation destroys cartilage and bone, joint deformity and dysfunction can occur, and may also appear on both sides of the thigh buttock cold. 3. Sciatic neuritis: it is an interstitial inflammation of the nerve caused by cold and infection. Mainly manifested along the sciatic nerve pathway, that is, the waist, buttocks, thighs, calves, and the back of the foot lateral radiating pain, cold. If the pain is recurrent, muscle atrophy of the lower limb on the affected side may occur over time, or claudication may occur. Thigh buttock side acid cold may have other reasons, it is recommended to go to the hospital in a timely manner, improve the examination to clarify the cause of the disease, give targeted treatment or treatment.