Merck Manual

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Frank Pessler

, MD, PhD, Helmholtz Centre for Infection Research

Reviewed/Revised Nov 2022
Topic Resources

Kyphosis is an abnormal curving of the spine that causes a humpback.

The upper back normally curves forward somewhat. Some children have a greater degree of curvature. The excessive curvature may be

  • Flexible

  • Fixed (structural)

In flexible kyphosis, children can straighten the spine by tightening their muscles and the backbones (vertebrae) are normal. The cause is not known. Muscle-strengthening exercises may help, but no other specific treatment is needed.

In fixed kyphosis, children cannot straighten the spine because several of the vertebrae in the upper back are wedge-shaped rather than rectangular. Usually, 3 or more vertebrae are involved. Rarely, infants are born with fixed kyphosis, but it more commonly develops later in life, usually in adolescence. There are many rare causes, including fractures, infections, and cancer, but the most common cause is Scheuermann disease Scheuermann Disease Kyphosis is an abnormal curving of the spine that causes a humpback. (See also Overview of Bone Disorders in Children.) The upper back normally curves forward somewhat. Some children have a... read more .

Kyphosis often causes no symptoms. Sometimes mild, persistent back pain develops. Kyphosis may be noticed only because it alters the body’s appearance. The shoulders may appear rounded. The upper spine may appear more curved than normal, or a hump may be visible. Some people have an appearance similar to those with Marfan syndrome Marfan Syndrome Marfan syndrome is a rare hereditary disorder of connective tissue, resulting in abnormalities of the eyes, bones, heart, blood vessels, lungs, and central nervous system. This syndrome is caused... read more Marfan Syndrome , in whom the limbs are much longer than the trunk.

Mild kyphosis that does not cause symptoms is sometimes detected only during a routine physical examination. A doctor may confirm the diagnosis of kyphosis by taking x-rays X-Rays X-rays are a type of medical imaging that use very low-dose radiation waves to take pictures of bones and soft tissues. X-rays may be used alone (conventional x-ray imaging) or combined with... read more of the spine.

Kyphosis: A Humpback

Kyphosis: A Humpback

Scheuermann Disease

Scheuermann disease is the most common form of fixed kyphosis. It usually begins in adolescence, affecting boys slightly more often than girls. The cause of Scheuermann disease is unknown, but it sometimes runs in families. Scoliosis Scoliosis Scoliosis is abnormal curvature of the spine. Scoliosis can be present at birth or can develop during adolescence. Mild forms may cause only mild discomfort, but more severe forms can cause... read more Scoliosis , a sideways curvature of the spine, also often develops in children with kyphosis (called kyphoscoliosis).

Severe kyphosis is more likely to cause discomfort and sometimes can restrict chest motion, causing lung disease.

Treatment of Scheuermann Disease

  • Reducing weight-bearing and strenuous activities

  • Rarely a brace or surgery

Mild kyphosis can be treated by reducing weight-bearing stress and by avoiding strenuous activities. The spine may straighten slightly with treatment, although symptoms may not lessen. It is unclear whether treating mild kyphosis prevents the curve from worsening.

When kyphosis is more severe, treatment most often consists of wearing a spinal brace or sleeping on a rigid bed. Treatment may lessen symptoms and prevent the curve from worsening.

Rarely, despite treatment, kyphosis worsens to such an extent that surgery is needed to straighten the spine.

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