Kyphosis (also called hunch-back or round-back) is a spinal deformity that occurs when the spine shows an excessive forward-facing curvature of the thoracic back bones (vertebrae), giving an abnormally rounded upper back appearance. There are natural kyphotic curves in the thoracic part of the spine, they help with balance and stability, as well keep the head aligned over the pelvis. Kyphosis is diagnosed if the natural curves in your thoracic spine are more than 50 degrees.