Scoliosis

Scoliosis (sko-lee-O-sis) is a lateral, or side-to-side, curvature of the spine that most often occurs gradually during childbood or adolescence.

What Is Scoliosis?

The word "scoliosis" comes from the Greek word meaning curvature. Everyone's backbone curves to  a  significant degree when  viewed from the side, which is necessary for proper movement and walking. When viewed from the front or back, however, the spine should appear as a straight line (or very nearly so). With scoliosis, the spine curves (from side to side) when viewed from the front or back, and this side-to-side curve may be S-shaped, which develops when another part of the spine develops a counterbalancing secondary curve. Depending on the degree of curvature, this condition may cause other physical problems, such as pain and breathing difficulties. The regions of the spine most commonly involved are the thoracic (tho-RAS-ik), or chest, region, and the lumbar (LUM-bar), or Iower back, region.

Scoliosis is a fairly common condition. It has been estimated that about 3 out of every 100 people have this disorder to some degree. Girls are about five times more likely than boys to develop scoliosis.

Causes, Known and Unknown

The most common form of scoliosis is called idiopathic (id-ee-o-PATH-ik), which means that the cause is unknown. Usually, scoliosis becomes apparent just prior to or during adolescence, when the body's rate of growth speeds up markedly. The curvature stops increasing after people have reached their mature height.

Rarely, scoliosis is a congenital (present at birth) abnormality of the vertebrae (VER-te-bray), or spinal bones, and continues to develop throughout childhood. Poliomyelitis (po-lee-o-my-uh-LYE-tis) has caused scoliosis in some people by paralyzing or weakening the spinal muscles on one side of the body.

Occasionally, an injury such as a disk prolapse (slipped disk) or a sprained ligament in the backbone can cause temporary scoliosis. When this happens, the curvature may be accompanied by back pain and sciatica. 

People who have scoliosis often have family members with the same condition. In 2007 a gene linked to adolescent idiopathic scoliosis was identified by researchers at Texas Scottish Rite Hospital for Children which confirmed a hereditary link for this type of scoliosis.

What Are the Signs and Symptoms of Scoliosis?

Because scoliosis can develop very gradually, there may be no observed signs or symptoms in its early stages. Often, the curvature is first noticed in a teenager indirectly: one shoulder may become noticeably higher than the other, or a dress or jacket may not hang straight.

Early symptoms of scoliosis may include an unusually tired or achy feeling in the lower back after standing or sitting for a long time.

For some, the curvature eventually may become more severe and easier to recognize. Severe scoliosis can cause chronic back pain. If the curvature exceeds an angle of about 40 or 45 degrees, it can interfere with breathing and affect heart function.