Scoliosis is detected by uneven shoulder heights, a loss of structural balance, or a change in posture.Look at a standing person from the side and you'll see the spine's natural curves. The lower back bends slightly inward and the upper part of the spine bows a little outward. Viewed from behind, however, the spine appears straight with very little side-to-side curvature — unless the person has a condition known as scoliosis.In scoliosis, the spine curves to one side. The spine affected by scoliosis may have an S shape or a C shape. Usually, a curve to one side develops, followed by a compensating bend in the opposite direction.Usually scoliosis is painless. Most cases are mild, requiring only follow-up and observation. In more extreme cases, the spine can rotate as well, resulting in ribs becoming prominent on one side of the body and narrowed spaces between ribs on the other side. Severe scoliosis can cause ongoing back pain and even difficulty with breathing.Very young children may have scoliosis, but adolescent idiopathic scoliosis (onset at 10 years or older) is the most common type. Scoliosis affects an estimated 2 percent of Americans, most often children.Scoliosis occurs rarely in adults. Sometimes, it's a worsening of a condition that began in childhood but wasn't diagnosed or treated. In other cases, adult scoliosis may result from a degenerative joint condition in the spine.