Lumbar pain when lying down is generally considered to be caused by lumbar degenerative lesions, supraspinous ligamentitis, gynecological diseases or urological diseases. 1. Degenerative lesions of the lumbar spine: commonly found in lumbar muscle strain, lumbar dorsal musculoskeletal fasciitis, etc., will appear in the lumbar soft tissues of the soreness, distension and pain, more obvious when lying down. 2. Supraspinous ligamentitis: pain and pressure in the supraspinous ligament area are obvious, and the lumbar pain will be felt when lying down. 3. Gynecological diseases: common gynecological diseases such as pelvic inflammatory disease and adnexitis will cause lumbar pain when lying down. 4. Urological diseases: for example, urinary tract stones, when the condition flares up, there will be obvious radioactive, paroxysmal pain, back pain when lying down. If you have soreness in the lower back when lying down, if it is difficult to relieve, it is recommended to go to the regular hospital for consultation and examination, such as ultrasound, X-ray, CT, MRI, etc., to identify the cause of the disease as soon as possible and timely treatment.