Causes

Lifting heavy objects incorrectly is the most common cause of lower back injury. Or you can throw your back out while over-reaching for a pencil or picking up your child. Acute pain, or pain that is recent or sudden, and does not extend to the leg is most commonly caused by a sprain or muscle tear. Weak muscles and ligaments may not be able to give the support and protection that the back needs.

Although uncommon, low back pain may mean a more serious medical problem. Other causes of lower back pain may include herniated discs, neuropathy, tumors, arthritis and compression fractures. Back pain may also mean kidney disease, infection or even diabetes.

Conditions associated with lower back pain other than sprains and strains

Bulging disc: The vertebrae discs take a lot of pressure. As these discs break down, cartilage may bulge or push onto the nerve root. Cauda equina syndrome is a rare complication of a ruptured disk where material presses against the bundle of lumbar and sacral nerves. If this condition is not treated, permanent nerve damage may occur.

Another herniated disc condition is called sciatica, or a "pinched nerve." The disc bulges against the sciatic nerve. You may feel shock-like or burning lower back pain and pain through the buttocks and down one leg. In rare cases, this condition may be caused by a cyst, tumor or other problem.

Spinal degeneration (spinal stenosis): This is from wear and tear of the discs. This kind of pressure causes the spinal canal to narrow. As a result, you may have stiffness in the back when you wake up or have pain after walking or standing for a long time.

Osteoporosis: Osteoporosis is considered the fragile bone disease where bones lose density and can easily be fractured. The dowager hump is when the vertebrae collapse on each other (compression fractures), causing pain and a hunchback appearance.

Fibromyalgia: This is a chronic disease marked by musculoskeletal pain, tiredness and tender spots in the neck, spine, shoulders and hips.

Osteoarthritis: This is a chronic disease marked by muscle and bone pain, tiredness and tender spots in the neck, spine, shoulders, and hips.

More on Acute Lower Back Pain

This article was reviewed and updated June 2007.