Back pain is just a symptom. Ache arising from other organs may be felt in the back. This is usually called referred pain. Many intra-abdominal disorders for instance appendicitis, aneurysms, bladder infections, kidney diseases, pelvic infections and ovarian disorders can cause pain referred to the back. Your doctor should remember this when estimating your pain. Nerve root syndromes are those that produce symptoms of nerve impingement often by reason of a herniation or bulging of the disc between the lower back bones. Sciatica is a pattern of nerve root impingement. Impingement pain tends to be sharp in one spot, and linked to numbness in the area of the leg that the affected nerve supplies.

Herniated discs are formed as the spinal discs deteriorate or grow thinner. The jellylike central segment of the disc bulges out of the central cavity and pushes against a nerve root. Intervertebral discs begin to deteriorate by the third decade of life, while herniated discs are found in a third of adults older than 20, counting the fact that only 3% of them produce symptoms of nerve impingement.

Spinal stenosis happens as intervertebral discs lose moisture and volume with age, which decreases the disc spaces. Even insignificant trauma under these circumstances can cause inflammation and nerve root impingement, which can produce classic sciatica without disc rupture.

Spinal degeneration is caused by changes in the disc that develop to degeneration. This together with the disease in joints of the low back provokes spinal canal narrowing. These changes in the disc and the joints make symptoms and can be seen on an x-ray. A person with spinal degeneration may have morning stiffness or pain whereas standing for a long time or walking even short distances.

Cauda equina syndrome is a medical emergency. Disc material develops into the spinal canal, which compresses the nerves. A person would feel pain, possible loss of sensation and bowel or bladder dysfunction. This could comprise lack of ability to control urination causing incontinence or the inability to begin urination.

Musculoskeletal pain syndromes that turn out to be a low back pain include myofascial pain syndromes and fibromyalgia.

Myofascial pain is characterized by pain and tenderness over localized areas, loss of range of motion in the involved muscle groups, and pain radiating in a characteristic distribution but restricted to a peripheral nerve. Pain relief is often reported when the involved muscle group is stretched.

Fibromyalgia results in pain and tenderness on 11 of 18 trigger points when touched, one of which is the low back area, as classified by the American College of Rheumatology. Generalized stiffness, fatigue, and muscle ache are reported.

Other skeletal causes of low back pain include osteomyelitis or sacroiliitis (infections of the bones of the spine). This pain is usually worse at night and is worse when sitting or standing for a long time.Tumors, possibly cancerous, can be a source of skeletal pain.