Kyphosis (from Greek κυφός (kyphos) 'hump') is an abnormally excessive convex curvature of the spine as it occurs in the thoracic and sacral regions.

[3] In the sense of a deformity, it is the pathological curving of the spine, where parts of the spinal column lose some or all of their lordotic profile.

These types of high-end curves typically do not respond well to conservative treatment and almost always warrant spinal fusion surgery, which can restore the body's natural degree of curvature.

Possible complications include inflammation of the soft tissue or deep inflammatory processes, breathing impairments, bleeding, and nerve injuries.

Even among those who do not develop serious complications, 5% of patients require reoperation within five years of the procedure, and in general it is not yet clear what one would expect from spine surgery during the long-term.

[4][5] Given that the signs and symptoms of spinal deformity cannot be changed by surgical intervention, surgery remains essentially a cosmetic choice.

[17] In Germany, a standard treatment for both Scheuermann's disease and lumbar kyphosis is the Schroth method, a system of physical therapy for scoliosis and related spinal deformities.

[18] It involves lying supine, placing a pillow under the scapular region and posteriorly stretching the cervical spine.

The legendary Comprachicos of the sort popularized in Hugo's similar work The Man Who Laughs are instead described as being able to turn able-bodied young children into hunchbacks, alongside a variety of other deformities, using poisons and mutilation, before selling their results into bondage as court dwarfs or freak show performers.