A normal spine, when viewed from behind, appears straight. However, a spine affected by kyphosis shows evidence of a forward curvature of the back bones (vertebrae) in the upper back area, giving an abnormally rounded or “humpback” appearance.
Kyphosis is defined as a curvature of the spine measuring 50 degrees or greater on an X-ray, a diagnostic test that uses invisible electromagnetic energy beams to produce images of internal tissues, bones, and organs onto film. The normal spine can bend from 20 to 45 degrees of curvature in the upper back area. Kyphosis is a type of spinal deformity.
Scoliosis is a sideways curvature of the spine that most often is diagnosed in adolescents. While scoliosis can occur in people with conditions such as cerebral palsy and muscular dystrophy, the cause of most childhood scoliosis is unknown.
Most cases of scoliosis are mild, but some curves worsen as children grow. Severe scoliosis can be disabling. An especially severe spinal curve can reduce the amount of space within the chest, making it difficult for the lungs to function properly.