For the swelling and pain on the left side of the waist, the following three main reasons are considered: first, the lumbar spine is in an incorrect posture for a long time, the muscle strength on both sides of the waist is unbalanced, so the muscles on one side will be in a state of long-term tension, spasm and strain, which is manifested as a feeling of swelling and pain. Second, various causes of scoliosis deformity, scoliosis of the convex side of the muscle in a long-term tension, will produce muscle strain, will also occur swelling pain feeling. Third, for intra-abdominal organ lesions can cause involving pain on the side of the waist, such as gastrointestinal disorders and lesions, urinary system inflammation and stones, can cause involving pain on the left side of the waist and back.