The lower back is primarily the lumbar spine, sacral spine, bilateral sacroiliac joints and their adjacent tissues, and can involve muscles, ligaments, fascia, posterior joints, lumbosacral joints or sacral skeletal joints. Every person has a history of lower back pain to a greater or lesser extent, mildly or severely. Often people say they have a lumbar disc herniation when they have lower back pain, but in fact not all lower back pain symptoms are caused by a lumbar disc herniation. There are many causes of lower back pain, which can be roughly divided into the following categories: (1) congenital or developmental abnormalities of the lumbar spine: including congenital lumbar fusion, hemivertebral deformity, occult spina bifida, lumbar sacralization, sacral lumbarization, spinal isthmus discontinuity or slippage, scoliosis, hypertrophy of the transverse process of the third lumbar vertebra, free spinous process, spinous process too large or too small, hooked spinous process, congenital lumbar spinal stenosis, etc. (2) Degenerative changes of the lumbar spine: including lumbar hypertrophic spondylitis, senile osteoporosis, lumbar disc herniation, secondary lumbar spinal stenosis, pseudolumbar spondylolisthesis, senile hunchback, lumbar degenerative osteoarthropathy, lower lumbar instability, etc. (3) Lower lumbar inflammation: including lumbar back fascial fibrositis, lumbar tuberculosis, sacroiliac arthritis, ankylosing spondylitis, rheumatoid arthritis, septic spondylitis, lumbar 3 transverse bursitis, lumbar intervertebral discitis, etc. (4) Lower back injury: including acute lumbar sprain, lumbar muscle strain, lumbar ligament injury, lumbar fracture, dislocation, sacrococcygeal injury, sacroiliac joint sprain, etc. (5) Lower back tumors: including primary and secondary tumors ① Primary benign tumors: such as osteoid osteoma, bone cyst, osteoblastoma, osteochondroma, osteochondroma, osteochondrodysplasia, etc. ② Primary tumors with malignant tendency: such as chordoma, giant cell tumor of bone, osteoblastoma, etc. ③ primary malignant tumors: such as malignant lymphoma, osteoblastoma, lumbosacral sarcoma, etc. (4) Breast cancer, prostate cancer, uterine cancer and other malignant tumors metastasizing to the lumbosacral region can produce lower back pain symptoms. (6) Disorders of adjacent tissues: such as sciatica, pear-shaped muscle syndrome, etc.; stones, pyelonephritis, perinephric abscess, etc. in the urinary system; peptic ulcer, chronic pancreatitis, etc. in the digestive system; uterine corporitis, adnexitis, uterine prolapse, pelvic tumor, etc. in obstetrics and gynecology; retroperitoneal tumor eroding the spine can also produce lower back pain. (7) Functional defects: such as poor body posture, pregnancy, flat feet, unequal lower limbs, and insufficient lumbar and hip muscle strength. (8) Others: toxic diseases, such as fluorosis; nutritional diseases, such as osteochondrosis; neurological diseases, such as hysteria, etc.