Home > Encyclopedia of Medicine > Kyphosis

Definition

Kyphosis is the extreme curvature of the upper back also known as a hunchback.

Description

The upper back bone (thoracic region), is normally curved forward. If the curve exceeds 50° it is considered abnormal (kyphotic).

Causes and symptoms

Kyphosis can be divided into three ages of acquisition—birth, old age, and the time in between.

• Spinal birth defects can result in a fixed, exaggerated curve. Vertebrae can be fused together, shaped wrong, extraneous, or partially missing. Congenital and hereditary defects in bone growth weaken bone and result in exaggerated curves wherever gravity or muscles pull on them. Dwarfism is such a defect.
• During life, several events can distort the spine. Because the natural tendency of the thoracic spine is to curve forward, any weakness of the supporting...