The cause is mostly loss of bone mass or osteoporosis
This is an abnormal outward curvature of the thoracic vertebrae of the upper back. Compression of the front portion of the involved vertebrae due to osteoporosis leads to forward bending of the spine (kyphosis) and creates a hump at the upper back.
The cause is usually loss of bone mass or osteoporosis: women in particular develop this after menopause. This painful postural change is not just a sign of age. It is an indication of advanced osteoporosis: the vertebral bodies in the spine have lost bone density due to loss of bone mass and have collapsed. These are called compression fractures.
Fractures of other bones without any recognizable cause or fractures that occur during everyday activities or movements are an indication of possible osteoporotic disease. Hip fractures after minor falls and wrist fractures while supporting weight are common. Ribs may even break while coughing.