[Etiology and diagnosis of chronic back pain].

Chronic low back pain is lumbar-sciatic pain of more than 3 months duration. It is necessary to classify back conditions into conditions with and without nerve root affection. In addition to herniated discs, spinal stenosis and intra- or extramedullary tumours, transdiscal ruptures may cause radicular symptoms and signs from a local inflammatory effect caused by the nucleus material affecting the epidural tissue. Low back pain without radicular affection accounts for 95% of all cases of chronic low back disability. Symptoms and signs, x-ray investigations, and laboratory data are dealt with in the structural and focal etiology of the pain. The relationship between psycho-social factors and low back pain is discussed.