Back Pain

What Causes Back Pain?

Common Causes Of Back Pain

The most common causes of lower back pain are sprains and strains.


Despite their size and strength, muscles of the lumbar spine can rip or tear. This is called a muscle “strain.”

A strain is the result of a heavy load or sudden force applied to the muscles before they are ready for activity. The muscle essentially rips, along with the blood vessels within the muscle tissue. This may cause bleeding into the injured area.

It can take up to two to three hours before sufficient bleeding or irritation sets in to produce significant pain. This can help explain why many people often can tolerate finishing the task at hand, only to suffer from intense pain later.

This tear in the muscle tissue is followed by symptoms such as:

  • Pain
  • Swelling
  • Muscle spasms


Sprains refer to an overstretching of one or more of the ligaments of the back. The ligaments can be stretched beyond their natural integrity and in some cases can completely tear.

It is common to have both ligament sprains and muscle strains occurring together. This is especially the case in severe falls and motor vehicle accidents.

Nice To Know:

Acute and intense low back pain often results from unspecific sprains and strains. Acute low back pain from lumbar strains and sprains can be accompanied by sciatica, a term used to describe pain extending down into the buttock and leg from the irritation of a larger nerve exiting the lumbar spine called the sciatic nerve.

Other Conditions Causing Back Pain

Other conditions that can cause back pain include:

  • Disc Injury
  • Spinal Stenosis
  • Osteoarthritis of the Spine
  • Spondylolisthesis
  • Ankylosing Spondylitis
  • Osteoporosis and Fractures of the Lumbar Spine
  • Pregnancy
  • Fibromyalgia

Disc Injury

herniated disc, also called a “slipped disc,” is a disc that bulges out from its position between two vertebrae. There are four types of disc herniation:

  • Disc bulge or protrusion results when the disc bulges out from between two vertebrae without rupturing its surrounding envelope, the annulus fibrosis.
  • Disc prolapse results when the inner jelly-like central part of the disc ( the nucleus pulposis), seeps into the outermost fibers of the surrounding envelope, the annulus fibrosis.
  • Disc extrusion results when a tear occurs in the surrounding envelope of the disc, and the inner jelly-like central part of the disc leaks out of the disc.
  • Sequestrateddisc is the term used when disc fragments are separated from the disc, coming to lie well outside the disc space in the spinal canal.

A herniated disc has the potential to cause compression against a nerve, producing what is called radicular pain. Radicular pain is also called sciatica. This pain is caused by compression of the nerves as they exit the spinal column. The pain may be felt radiating into the buttock or down the leg, and may be accompanied by a sensation of numbness or tingling in the leg.

Spinal Stenosis

Stenosis means a constriction or narrowing. Spinal stenosis refers to narrowing of the spinal canal, a condition usually affecting people over age 50.

It results mostly from degenerative changes, or osteoarthritis, in the spine, particularly from bony formations called osteophytes, which form around the joints of the spine. These bony overgrowths, together with thickening of the ligaments inside the spinal canal, narrow the available space in the spinal canal for the spinal cord and its nerves, and may place pressure on these structures.

The condition may cause back pain and pain in the thigh or leg, that often is made worse with long periods of standing or walking, particularly downhill, as well as weakness in the legs.

When symptoms are severe and persistent, and do not respond to conservative therapy, surgical treatment may be necessary to take pressure off affected nerves.

Osteoarthritis Of The Spine

Osteoarthritis refers to joint damage that results from “wear and tear.” The cartilage (the tissue that lines the joints) between the vertebrae may become increasingly damaged. This may affect a single joint or any number of the joints of the spine. These changes to the joints are also known as degenerative changes.

The main features of osteoarthritis of the spine are the development of bony outgrowths, called spurs, along the junction of vertebral bodies and discs. This is believed to be a natural result of stresses applied to the spine throughout life. Other features are narrowing of the joint due to the loss of cartilage between the affected vertebrae, and sometimes small areas of erosion of the bone beneath the joint.

Nice To Know:

Degenerative changes in the disc are probably related to aging. Any trauma in addition to these changes may speed up the process of degeneration. For example, an injury that causes a fracture to the vertebrae near the disc can make the disc more likely to degenerate in the future.


Spondylolisthesis is a condition in which one vertebra slips forward on the one beneath it. It may result from a number of causes, including trauma to the spine or osteoarthritis (wear and tear) of the spine, or it may have been acquired from birth.

The amount the vertebra has slipped forward on the one beneath it may be minimal or very significant.

  • There may be no symptoms or there may be back pain and the back may feel stiff.
  • If the slip has caused pressure on a nerve root, pain may be felt in the buttocks or thigh.
  • With a major slip, an increase in the bend of the lower back can be noticed (called increased lordosis).

Treatment depends on the severity of the condition and the symptoms. This may range from simple exercises and physical therapy to spinal fusion (hyperlink glossary) to stabilize the spine.

Ankylosing Spondylitis

Ankylosing spondylitis is a type of arthritis that primarily affects the spine. “Ankylosing,” in Greek, means, “causing stiffness and immobility of a joint,” and “spondylitis” means inflammation of one or more vertebrae.

Ankylosing spondylitis causes inflammation of the ligaments and tendons that connect the vertebrae and ultimately results in fusion of the spine. This occurs because the inflammation causes some damage to the bone, and the body heals this damage by growing new bone, which replaces the elastic soft tissue at the back of the spine. This can result in stiffness and pain. In some cases, as the fusion progresses, the spine curves forward, causing a person to stoop.

Ankylosing spondylitis occurs sometimes in people with psoriasis and inflammatory bowel disease.

Stiffness and pain usually begins in the pelvis and at the base of the spine, and progresses upward through the back and to the neck. The back is generally stiff in the morning and improves during the day. Early diagnosis and treatment can control the pain and stiffness.

For more detailed information about Ankylosing Spondylitis, GO TO Ankylosing Spondylitis.

For more information about psoriasis, GO TO Psoriasis.

For more information about inflammatory bowel disease, GO TO Ulcerative Colitis.

Osteoporosis And Fractures Of The Lumbar Spine

Osteoporosis is a condition in which bone density and bone strength decreases, making a person more susceptible to fractures. It is a major cause of bone fractures in postmenopausal women and older persons in general.

Because the signs of osteoporosis are subtle and can be easily missed, many people do not know they have osteoporosis until a bone actually breaks. In many cases it is the vertebrae that fracture, causing back pain or deformity. The hip and wrist are also common sites of fractures resulting from osteoporosis.

After menopause, osteoporosis is much more common in women. Bone loss in the spine results in reduced bone strength, and this can easily lead to fractures of the spine.

For more detailed information about osteoporosis, go to Osteoporosis.


A woman’s body undergoes significant hormonal and physical changes during the nine months of pregnancy. For most women, this can lead to back pain as an unavoidable side effect during this time.

Early in pregnancy, certain hormonal changes result in increased joint laxity. As a result, the spine, abdominal and back muscles, and posture of the low back change and become more relaxed.

Poor posture and poor muscle tone prior to pregnancy can affect how the back adjusts. The lumbar (lower back) curve begins to increase slightly as the pelvis tilts backward. This posture begins to influence the weakened and now fatigued lower back muscles. A woman may experience mildly painful spasms, which can be the first sign of a persistent backache in early pregnancy.

As the pregnancy progresses:

  • The abdomen protrudes.
  • Both gravity and hormonal changes continue to relax the muscles of the low back and abdomen.
  • The increased lumbar curve places stress on the lower back muscles and lumbar spine.
  • The chance of back pain rises significantly with activity.
  • Without treatment, the frequency of muscle spasms and pain may increase.

Back pain during pregnancy can usually be managed with:

  • Using better posture
  • Learning about body mechanics (proper sitting, bending, lifting, etc.)
  • Using an external brace or support
  • Following a proper exercise plan

Sciatica during pregnancy can also develop from the increased size of the baby itself. The growing fetus can place pressure directly on the nerves of the lumbar area, causing direct pressure and pain. Sciatica almost always goes away after delivery.


Fibromyalgia may cause chronic back pain and is believed to be a result of inflammation of the body’s connective tissue. The condition is characterized by widespread muscle pain, fatigue, and multiple tender points on the body.

Fibromyalgia is more common than most people realize. In many sufferers, pain is present most of the time and may last for years. The severity of the pain goes up and down, and the location of the back pain as well as the generalized pain can vary.

Low back pain resulting from a diagnosis of fibromyalgia is real, but can also be subjective. Many people with this condition find that emotional stress makes the pain worse. Fatigue is also a common aspect of this condition. Chronic pain, along with anxiety about the problem and how to get well, can be fatiguing by itself. In addition, the inflammatory process within the body produces chemicals that are known to cause fatigue.

Nice To Know:

In 1990, the America College of Rheumatology developed criteria that health care practitioners can use to diagnose fibromyalgia. According to the criteria, a person is considered to have fibromyalgia if she or he has widespread pain in combination with tenderness in at least 11 of the 18 tender spot (trigger point) sites.


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