What causes back pain, and how to prevent it
It can happen while you're hauling boxes to the attic, gardening in the yard or even sitting in front of a computer too long.

Back pain: It's one of the most common medical problems in the United States, according to the National Institutes of Health.

The pain can range from a sharp stabbing that locks you in your tracks to a dull, chronic ache that slowly gets worse over time. Most people will have back pain at some point in their life, according to the National Institute of Arthritis and Musculoskeletal and Skin Diseases, which is a division of the National Institutes of Health.

People who have had back strains and pains know how debilitating it can be. Sometimes every move is uncomfortable. But a basic understanding of how the spine works with back muscles, along with a regular routine of stretching and common-sense, can help prevent or relieve the pain.

Risk Factors

Some people are more prone to getting back pain than others. The risk factors include:

Age: Back pain might start, or begin a recurring pattern, for people in their 30s.

Being out of shape: Lack of exercise can lead to tight or weak muscles, which don't support the spine well. Weak or tight muscles are also more likely to spasm, according to the national musculoskeletal institute.

Obesity: Too much weight can strain back muscles and disks in between the vertebrae of the spine.

Smoking: Disks between the vertebrae have a soft center — a nucleus pulposus — and a tougher exterior, annulus fibrosus. The disks absorb shock and vibration when you run or walk. To stay healthy, the disks need nutrients and water, and smoking restricts the circulatory system from providing both.

Work: Heavy lifting or pulling, particularly while twisting the torso, can pull muscles or force a disk out of place. Sitting also puts pressure on the lower back. Working at a desk can push disks out from between vertebrae, sometimes squeezing nerves that run down the spine and branch out to the left and right.

"Sitting is a huge factor in chronic pain," said Laurie Devaney, clinical instructor at Nayden Rehabilitation at the University of Connecticut in Storrs. "You're getting more compression in your spine in sitting than in standing."

Family History: Some back problems are passed down in genes — such as a type of spinal arthritis called ankylosing spondylitis, according to the national musculoskeletal institute.

What Causes The Pain?

Back pain is generally either spasms in one or more muscles, or the gradual degeneration or collapsing of disks between vertebrae in the spine, or both.

Acute pain typically last less than six weeks and is a sharp pain that can be treated with rest and over-the-counter pain relievers. Chronic pain lasts more than three months and typically requires a combination of prescription medication, physical therapy and, in some cases, surgery.

Disks, which are sized to vertebrae, can sometimes bulge, which causes them to flatten out like a burger being squeezed beyond the edges of a bun. In some cases, the tough exterior of the disk can rupture and the soft center will squeeze out.

The center, which is the consistency of uncooked shrimp, can poke out and press against a nerve in the spine. In some cases, a disk can pinch the sciatic nerve. A pinched sciatic nerve can cause pain along the nerve, into the buttocks on one side, down the hamstring, on the outer side of the lower leg all the way to the foot. That pain, called sciatica, is also associated with numbness and tingling in one leg. Go see a doctor if you feel tingling or numbness.

One in three adults older than 20 show signs of herniated disks, but only about 3 percent of those disks cause pain symptoms, according to the University of Maryland Medical Center.