Scoliosis is an abnormal curvature of the spine. Instead of going from top to bottom in a relatively straight line, a spine with scoliosis may appear to have a side-to-side “S-shaped” or “C-shaped” curve. Mild degrees of scoliosis won’t cause you any problems. However, more severe cases of scoliosis can result in pain, weakness, and low self-esteem because of obvious cosmetic deformity. Very severe scoliosis may cause heart and lung problems if those organs are overly cramped in an abnormally shaped chest cavity.

Scoliosis is usually classified by the age at which it appears to have begun:

Most cases of scoliosis begin when a child is around 8 or 10 years old, and the abnormal curvature may progress as the child continues to grow.

Although there are some medical conditions that are associated with an increased risk of scoliosis, no one knows exactly what causes most cases of scoliosis. Therefore, the vast majority of cases are considered idiopathic, which means of unknown origin. The most common type of scoliosis (adolescent scoliosis) is idiopathic. Infantile and juvenile scoliosis may be:

This type occurs when the spine appears abnormal due to muscle spasms that are temporarily pulling it out of alignment, or due to one leg being shorter than the other.

This type occurs when the spine itself is abnormal due to another medical condition, such as a birth defect (including spina bifida and meningomyelocele), muscular dystrophy , spinal tumor, cerebral palsy , injury, or Marfan syndrome .

Scoliosis affects about three to four of every 1,000 people.

Last Reviewed September 2012