Everyone's spine has natural curves. These curves round our shoulders and make our lower back curve slightly inward. But some people have spines that also curve from side to side. Unlike poor posture, these curves can't be corrected simply by learning to stand up straight.

This condition of side-to-side spinal curves is called scoliosis. On an X-ray, the spine of an individual with scoliosis looks more like an "S" or a "C" than a straight line. Some of the bones in a scoliotic spine also may have rotated slightly, making the person's waist or shoulders appear uneven.

Who gets scoliosis?

Scoliosis affects a small percentage of the population, approximately 2 percent. However, scoliosis runs in families. If someone in a family has scoliosis, the likelihood of an incidence is much higher - approximately 20 percent. If anyone in your family has curvature of the spine, you should be examined for scoliosis.

Children - The vast majority of scoliosis is "idiopathic," meaning its cause is unknown. It usually develops in middle or late childhood, before puberty, and is seen more often in girls than boys. Though scoliosis can occur in children with cerebral palsy, muscular dystrophy, spinal bifida and other miscellaneous conditions, most scoliosis is found in otherwise healthy youngsters.

Adults - Scoliosis usually develops during childhood, but it also can occur in adults. Adult scoliosis may represent the progression of a condition that actually began in childhood, and was not diagnosed or treated while the person was still growing. What might have started out as a slight or moderate curve has progressed in the absence of treatment.

In other instances, adult scoliosis can be caused by the degenerative changes of the spine. Other spinal deformities such as kyphosis or round back are associated with the common problem of osteoporosis (bone softening) involving the elderly. As more and more people reach old age in the U.S., the incidence of scoliosis and kyphosis is expected to increase.

If allowed to progress, in severe cases adult scoliosis can lead to chronic severe back pain, deformity, and difficulty in breathing.