Back pain is one of the most common health complaints. Almost everyone will have back pain at some time in their life. Most of the time, the exact cause of the pain cannot be found.

This article discusses long-term (chronic) low back pain. For information on other types of low back pain that occur suddenly, see: Low back pain.

One single event may not cause your pain. You may have been doing many things improperly -- such as standing or lifting -- for a long time. Then suddenly, one simple movement (such as reaching for something or bending from your waist) leads to the feeling of pain.

The specific part of your back that is responsible for your pain is sometimes difficult to identify. There are several possible causes of low back pain:

• Certain medical conditions such as fibromyalgia
• Herniated disc (part of a spinal disc pushes onto nearby nerves)
• Strain or tears to the muscles or ligaments supporting the back
• Degenerative disc disease
• Pelvic injury or fracture
• Piriformis syndrome (a pain disorder involving a narrow muscle in the buttocks)
• Spinal stenosis (narrowing of the spinal canal)
• Small fractures to the spine from osteoporosis
• Spine curvatures (such as scoliosis or kyphosis), which may be inherited and seen in children and teens

You are at particular risk for low back pain if you:

• Are over age 30
• Are pregnant
• Feel stressed or depressed
• Have arthritis or osteoporosis
• Smoke
• Do not exercise
• Are overweight
• Have a job that requires heavy lifting, a lot of bending and twisting, or whole body vibration (such as truck driving or using a sandblaster)