Definition of Paget's disease of the bone:

Paget's disease is a disorder that involves abnormal bone destruction and regrowth, which results in deformity.

Causes, incidence, and risk factors:

The cause of Paget's disease is unknown, although it might have to do with genes or a viral infection early in life.

The disease occurs worldwide, but is more common in Europe, Australia, and New Zealand.

In people with Paget's disease, there is an abnormal breakdown of bone tissue, followed by abnormal bone formation. The new bone is bigger, but weakened and filled with new blood vessels.

The disease may only be in one or two areas of the skeleton, or throughout the body. It often involves bones of the:

• Arm
• Collar
• Leg
• Pelvis
• Spine