Scoliosis (sko-lee-O-sis) is a lateral, or side-to-side, curvature of the spine that most often occurs gradually during childhood or adolescence.

Normal spine compared to a spine affected by scoliosis. Illustration by Electronic

Normal spine compared to a spine affected by scoliosis. Illustration by Electronic
Illustrators Group. © 2016 Cengage Learning®.

What Is Scoliosis?

The word scoliosis comes from the Greek word meaning curvature. Everyone's backbone curves to a significant degree when viewed from the side, and this curve is necessary for proper movement and walking. When viewed from the front or back, however, the spine should appear as a straight line (or very nearly so). With scoliosis, the spine curves from side to side when viewed from the front or back. This side-to-side curve may be S-shaped, and can occur when another part of the spine develops a counterbalancing secondary curve. Depending on the degree of curvature, this condition may cause other physical problems such as pain and breathing difficulties. The regions of the spine most commonly involved are the thoracic (tho-RAS-ik), or chest region, and the lumbar (LUMbar), or lower-back region.

Scoliosis is a fairly common condition. It has been estimated that about three out of every 100 people have this disorder to some degree. Girls are about five times more likely than boys to develop scoliosis.

What Are the Causes of Scoliosis?

The most common form of scoliosis is called idiopathic (id-ee-o-PATH-ik), which means that the cause is unknown. Usually, scoliosis becomes apparent just prior to or during adolescence, when the body's rate of growth speeds up markedly. The curvature stops increasing after people have reached their mature height.

Rarely, scoliosis is a congenital (present at birth) abnormality of the vertebrae (VER-te-bray), or spinal bones, and continues to develop throughout childhood. Poliomyelitis *

In the early 1900s, teenagers who had to wear back braces for scoliosis faced some very uncomfortable choices. As if being tortured, they were strapped to racks in an attempt to straighten their backs. Later on, metal jackets that weighed up to 30 pounds were worn to try to reduce the curvature. Lighter jackets that were made of plaster of Paris came next, but they were often hot and itchy.

Now back braces are much improved. Many are made of lightweight materials and do not have to be worn all the time. There are several different types to choose from to suit the teenager's particular requirements. Some are worn only during sleep. Others can be worn under clothing so that they are not visible. There are also low-profile types that come up under the arms and are quite comfortable.

Wearing a back brace sometimes causes emotional problems. Some teenagers may resist the idea of wearing a back brace because they fear their friends or classmates may reject or ridicule them. Counseling or support groups often are helpful in sharing experiences and problems and should be considered as part of the treatment.

As medical engineers continue to design improvements in these devices, future back braces will undoubtedly be even more adaptable.

Occasionally, an injury such as a disk prolapse (slipped disk) or a sprained ligament * in the backbone can cause temporary scoliosis. When this injury occurs, the curvature may be accompanied by back pain and sciatica * .

People who have scoliosis often have family members with the same condition. In 2007 a gene linked to adolescent idiopathic scoliosis was identified by researchers at Texas Scottish Rite Hospital for Children, which confirmed a hereditary link for this type of scoliosis.

What Are the Signs and Symptoms of Scoliosis?

Because scoliosis can develop very gradually, there may be no observed signs or symptoms in its early stages. Often, the curvature is first noticed in a teenager indirectly: One shoulder may become noticeably higher than the other, or a dress or jacket may not hang straight.

Early symptoms of scoliosis may include an unusually tired or achy feeling in the lower back after standing or sitting for a long time.

For some, the curvature eventually may become more severe and easier to recognize. Severe scoliosis can cause chronic * back pain. Back pain associated with scoliosis may signal the presence of an underlying condition like spondylolysis, which is a defect in a part of the facet joint * which can cause instability in the vertebra. If the curvature exceeds an angle of about 40 or 45 degrees, it can interfere with breathing and affect heart function.

How Is Scoliosis Diagnosed?


Scoliosis is not always easy to diagnose, especially if it does not hurt or have visible signs. A physical examination of the spine, hips, and legs is the first step, followed by an x-ray if needed. Physical signs that may be evident include shoulders which are not level and a protruding collarbone. In the most commonly observed pattern of curvature, the right shoulder is rotated forward. Leg length should also be measured, as many people with scoliosis experience differences in the lengths of their legs.

In the United States, public schools often do a simple test for scoliosis called the forward-bending test. The school nurse or another staff member has students bend over parallel to the floor with their shirts off to check for curvature. If scoliosis is suspected, the student is referred to a family doctor for further evaluation. The doctor might want to have an x-ray taken for a clearer view of the spine.

The severity of scoliosis is diagnosed by determining the extent of curvature of the spine. The curvature is the angle of slant of the spinal bones measured in degrees. Scoliosis is typically diagnosed when the degree of the curvature of the spine exceeds 10 degrees. Children who are diagnosed with scoliosis between the ages of 3 to 10 years are much more likely to experience curves that progress and require surgical correction.

How Is Scoliosis Treated?

In idiopathic scoliosis, the choice of treatment depends largely on the severity of the condition. If the angle of curvature is slight (e.g., 10 to 15 degrees) nothing may need to be done other than having regular checkups to make sure the curvature does not worsen. Somewhat greater curvatures can be treated by wearing any of several types of back braces. An angle of curvature of 40 degrees or more may mean that a corrective operation is needed.

Living with Scoliosis

Fortunately, much of the deformity of scoliosis can be prevented if the condition is detected early. In most instances, no lifestyle changes are needed, and people can carry on with their normal activities.

See also Genetic Diseases: Overview • Poliomyelitis • Sciatica • Slipped (Herniated) Disk


Books and Articles

Weiss, Hans-Rudolf. I Have Scoliosis: A Guidebook for Patients, Family Members, and Therapists. Saarbrücken, Germany: Lambert Academic Publishing, 2013.

Weiss, Hans-Rudolf, Christa Lehnert-Schroth, and Marc Moramarco. Schroth Therapy: Advancements in Conservative Scoliosis Treatment. Saarbrücken, Germany: Lambert Academic Publishing, 2015.


National Institute of Arthritis and Musculoskeletal and Skin Diseases. “Questions and Answers about Scoliosis in Children and Adolescents.” (accessed July 6, 2016).


National Institute of Arthritis and Musculoskeletal and Skin Diseases. 1 AMS Cir., Bethesda, MD 20892-3675. Toll-free: 877-226-4267. Website: (accessed July 6, 2016).

National Scoliosis Foundation. 5 Cabot Pl., Stoughton, MA, 02072. Toll-free: 800-673-6922. Website: (accessed July 6, 2016)

Scoliosis Care Foundation. 1085 Park Ave., Suite 1E, New York, NY 10128. Toll-free: 800-391-8837. Website: (accessed July 6, 2016).

Scoliosis Research Society. 555 East Wells St., Suite 1100, Milwaukee, WI 53202-3823. Telephone: 414-289-9107. Website: (accessed July 6, 2016).

* poliomyelitis (po-lee-o-my-uh-LYE-tis) is a disorder caused by the poliovirus that involves damage to nerve cells. It may lead to weakness and deterioration of the muscles and paralysis.

* ligament (LIG-a-ment) is a fibrous band of tissue that connects bones or cartilages (CAR-ti-lij-ez), serving to support or strengthen joints.

* sciatica (sy-AT-i-ka) is pain along the course of either of the sciatic (sy-AT-ik) nerves, which run through the pelvis and down the backs of the thighs.

* chronic (KRAH-nik) means lasting a long time or recurring frequently.

* facet (fas-it) joint refers to small hinge-like joints located at the back of the spine that link the vertebrae together.

  This information is not a tool for self-diagnosis or a substitute for professional care.