| Paget's disease is the second most common bone | | | | prevalence of familial Paget's disease (where more |
| disease. Paget's disease is a chronic bone disorder | | | | than one family member has the disease) ranges |
| that is due to irregular breakdown and formation of | | | | from 10 to 40% in different parts of the world. It is |
| bone tissue.The disease occurs worldwide, but is | | | | usually localized to one bone, but can involve many |
| more common in Europe, Australia, and New Zealand | | | | bones. The actual cause of Paget's disease is not |
| -- where it is seen in up to 5% of the elderly | | | | known. Paget's disease is also known as osteitis |
| population. Paget's disease can cause bones to | | | | deformans. The disease may localize to one or two |
| expand and weaken and may result in bone pain, | | | | areas within the skeleton, or become widespread. |
| arthritis, bone deformity and fractures. Men and | | | | Frequently, bones of the pelvis, leg, spine, arm, or |
| women are approximately equally affected. The | | | | the collar bone are involved. The effect on the skull |
| prevalence of Paget's disease ranges from 1.5 to 8% | | | | may enlarge head size and cause hearing loss, if the |
| depending on age and country of residence. The | | | | cranial nerves are damaged by the bone growth. |