Abnormal curvature of the spine.

Beginning in childhood or adolescence, scoliosis curves the spine so that the shape of the body is distorted. The disease can cause pain, deformity, and other medical problems if not properly treated. Scoliosis is defined medically as a sideways (lateral) spinal curvature of eleven degrees or more. Only lateral curvatures constitute scoliosis, as distinct from an excessive rounding of the back with rounded shoulders and sunken chest (hyperkyphosis) or an abnormal forward curve of the lower back (hyperlordosis, also called swayback). Scoliosis eventually pulls the rib cage out of its normal position, crowding the ribs inside the curve and pulling those outside it apart. If severe enough, it can damage internal organs and impair breathing. In cases where scoliosis is painful, the pain is generally increased by bending, extended standing, and heavy work.

The lateral curvatures of scoliosis are either C- or S-...