Hunchback is a nonmedical term for the forward bending of the spine. Doctors use the term kyphosis to describe this condition. A severe case of kyphosis results in a rounded or sharp prominence of the upper part of the back. Because this part of the back sticks out like a big hump, the condition is sometimes called humpback. Kyphosis is caused by any condition that deforms the bones of the upper part of the spine so that the person is bent forward. Diseases that cause kyphosis include tuberculosis, syphilis, and rheumatoid arthritis. Fractured spinal bones also may cause a hump in the back.
