What is
Paget's Disease?

Paget's disease of the bone (osteitis deformans) is a chronic skeletal disorder, which may result in enlarged or deformed bones in one or more regions of the skeleton. Excessive bone breakdown and formation can result in bone, which is dense but fragile.

In many cases, there may be no Paget's disease symptoms. Many patients who have Paget's disease do not know they have it since the bone disease may be so mild that it is not diagnosed.

Sometimes the patient's Paget's disease symptoms are confused with arthritis or other bone disorders. In other cases, the diagnosis is made only after complications have developed. When Paget's disease symptoms do occur, they are usually in advanced cases, and they can include: bone pain, arthritis, fractures, bowing of limbs, and hearing loss if Paget's disease affects the skull.

The causes of Paget's disease are still not clearly defined. Research suggests that Paget's disease may be caused by a “slow virus” infection of bone, a condition that is present for many years before symptoms appear. There is also a hereditary factor since the bone disease is sometimes present in more than one member of a family. This hereditary factor may be the reason that members of a family who have Paget's disease are susceptible to the suspected virus.

Any bone can be affected in Paget's disease. Paget's disease occurs most frequently in the spine, skull, pelvis and bones of the lower extremities (thighs and lower legs). Some patients will have only one affected bone, while others may have two, three, or more affected bones.

Paget's disease is the second most common bone disease in the United States, after osteoporosis. Paget's disease is rarely diagnosed in people under 40. More men than women develop Paget's disease. Prevalence in the population ranges from 1.5 percent to 8 percent in older adults, depending on the patient's age and where he or she lives. During the last eight years, several effective therapies for Paget's disease have been approved in the United States. However, many patients still have difficulty finding appropriate treatment for Paget's disease.