Mechanical low back pain
Lumbar strain
Degenerative disease
Discs (spondylosis)
Facet joints (osteoarthritis)
Spondylolisthesis
Herniated disc
Spinal stenosis
Osteoporosis
Fractures
Congenital disease
Severe kyphosis
Severe scoliosis
Possible type II or type IV transitional vertebra*
Possible spondylolysis
Possible facet joint asymmetry
Nonmechanical spine disease
Neoplasia
Multiple myeloma
Metastatic carcinoma
Lymphoma and leukemia
Spinal cord tumors
Retroperitoneal tumors
Infection
Osteomyelitis
Septic discitis
Paraspinous abscess
Epidural abscess
Inflammatory arthritis (often HLA-B27-associated)
Ankylosing spondylitis
Psoriatic spondylitis
Reactive arthritis
Inflammatory bowel disease
Scheuermann disease (osteochondrosis)
Paget disease
Visceral disease
Pelvic organs
Prostatitis
Endometriosis
Chronic pelvic inflammatory disease
Renal disease
Nephrolithiasis
Pyelonephritis
Perinephric abscess
Aortic aneurysm
Gastrointestinal disease
Pancreatitis
Cholecystitis
Penetrating ulcer
Fat herniation of lumbar space
HLA: human leukocyte antigen.
* A transitional vertebra is a congenital anomaly in which there is a naturally occurring articulation or bony fusion between the transverse processes of L5 and the sacrum, but there is still a small remnant disc space between L5 and the sacrum. Type II means that one or both transverse processes appear to form a diarthrodial joint with the sacrum, but there is no bony fusion. Type IV means that there is a type II abnormality on one side and a complete bony fusion on the opposite side.