Over-activity

One of the more common causes of low back pain is muscle soreness from over-activity. Muscles and ligament fibers can be overstretched or injured
This is often brought about by that first softball or golf game of the season, or too much yard work or snow shoveling in one day. We are all familiar with this "stiffness" and soreness in the low back — and other areas of the body — that usually goes away within a few days

Disk Injury

Some people develop low back pain that does not go away within days. This may mean there is an injury to a disk.

Disk tear

Small tears to the outer part of the disk (annulus) sometimes occur with aging. Some people with disk tears have no pain at all. Others can have pain that lasts for weeks, months, or even longer. A small number of people may develop constant pain that lasts for years and is quite disabling. Why some people have pain and others do not is not well understood

Disk herniation

Another common type of disk injury is a "slipped" or herniated disc

Herniated disk.

A disk herniates when its jelly-like center (nucleus) pushes against its outer ring (annulus). If the disk is very worn or injured, the nucleus may squeeze all the way through. When the herniated disk bulges out toward the spinal canal, it puts pressure on the sensitive spinal nerves, causing pain.
Because a herniated disk in the low back often puts pressure on the nerve root leading to the leg and foot, pain often occurs in the buttock and down the leg. This is sciatica.
A herniated disk often occurs with lifting, pulling, bending, or twisting movements.

Disk degeneration.

With age, intevertebral disks begin to wear away and shrink. In some cases, they may collapse completely and cause the facet joints in the vertebrae to rub against one another. Pain and stiffness result.
This "wear and tear" on the facet joints is referred to as osteoarthritis. It can lead to further back problems, including spinal stenosis.

 

Spondylolisthesis.

Degenerative Spondylolisthesis (Spon-dee-low-lis-THEE-sis). Changes from aging and general wear and tear make it hard for your joints and ligaments to keep your spine in the proper position. The vertebrae move more than they should, and one vertebra can slide forward on top of another. If too much slippage occurs, the bones may begin to press on the spinal nerves.

 

Spinal Stenosis

Spinal stenosis occurs when the space around the spinal cord narrows and puts pressure on the cord and spinal nerves. When intervertebral disks collapse and osteoarthritis develops, your body may respond by growing new bone in your facet joints to help support the vertebrae. Over time, this bone overgrowth - called spurs - can lead to a narrowing of the spinal canal. Osteoarthritis can also cause the ligaments that connect vertebrae to thicken, which can narrow the spinal canal.

 

Spinal Stenosis

Spinal stenosis occurs when the space around the spinal cord narrows and puts pressure on the cord and spinal nerves. When intervertebral disks collapse and osteoarthritis develops, your body may respond by growing new bone in your facet joints to help support the vertebrae. Over time, this bone overgrowth - called spurs - can lead to a narrowing of the spinal canal. Osteoarthritis can also cause the ligaments that connect vertebrae to thicken, which can narrow the spinal canal.

 

Scoliosis

This is an abnormal curve of the spine that may develop in children, most often during their teenage years. It also may develop in older patients who have arthritis. This spinal deformity may cause back pain and possibly leg symptoms, if pressure on the nerves is involved.

 

Additional Causes

There are other causes of back pain, some of which can be serious. If you have vascular or arterial disease, a history of cancer, or pain that is always there despite your activity level or position, you should consult your primary care doctor.

Symptoms

Back pain varies. It may be sharp or stabbing. It can be dull, achy, or feel like a "charley horse" type cramp. The type of pain you have will depend on the underlying cause of your back pain.
Most people find that reclining or lying down will improve low back pain, no matter the underlying cause.
People with low back pain may experience some of the following:

Back pain may be worse with bending and lifting.

Sitting may worsen pain.

Standing and walking may worsen pain

Back pain comes and goes, and often follows an up and down course with good days and bad days.

Pain may extend from the back into the buttock or outer hip area, but not down the leg

Sciatica is common with a herniated disk. This includes buttock and leg pain, and even numbness, tingling or weakness that goes down to the foot. It is possible to have sciatica without back pain

Regardless of your age or symptoms, if your back pain does not get better within a few weeks, or is associated with fever, chills, or unexpected weight loss, you should call your doctor.

Tests and Diagnosis

Medical History and Physical Examination After discussing your symptoms and medical history, your doctor will examine your back. This will include looking at your back and pushing on different areas to see if it hurts. Your doctor may have you bend forward, backward, and side to side to look for limitations or pain.
Your doctor may measure the nerve function in your legs. This includes checking your reflexes at your knees and ankles, as well as strength testing and sensation testing. This might tell your doctor if the nerves are seriously affected.

Imaging Tests

Other tests which may help your doctor confirm your diagnosis include:

X-rays.

Although they only visualize bones, simple X-rays can help determine if you have the most obvious causes of back pain. It will show broken bones, aging changes, curves, or deformities. X-rays do not show disks, muscles, or nerves

Magnetic resonance imaging (MRI).

This study can create better images of soft tissues, such as muscles, nerves, and spinal disks. Conditions such as a herniated disk or an infection are more visible in an MRI scan.

Computerized axial tomography (CAT) scans

If your doctor suspects a bone problem, he or she may suggest a CAT scan. This study is like a three-dimensional X-ray and focuses on the bones.

Bone scan

A bone scan may be suggested if your doctor needs more information to evaluate your pain and to make sure that the pain is not from a rare problem like cancer or infection.

Bone density test.

If osteoporosis is a concern, your doctor may order a bone density test. Osteoporosis weakens bone and makes it more likely to break. Osteoporosis by itself should not cause back pain, but spinal fractures due to osteoporosis can.