Low back pain is a frequent source of disability during the productive years of life. Repeated trauma is a major causative factor. Maintaining ideal body weight and good muscle tone, especially of the abdominal musculature, can minimize low back pain. Lumbar disc protrusion and extrusion may be treated by medical therapy, by neurosurgical intervention or possibly by chemonucleolysis. Other important causes of back pain are arthritis, facet disease and spinal stenosis. Evaluation of low back pain should include tests to uncover a psychogenic source.