The bone may enlarge in diameter, though, and it can become painful and break easily. Any bone can be affected, but the most common sites are the spine, skull, pelvis, and legs. Some patients may have only one affected bone, while others may have two or more. The disease usually does not spread to unaffected bones. Common deformities include bowed legs, an enlarged head or pelvis, and a curved back.
Pagetic bone can affect other parts of the body, causing added problems.
For example, it can change bones around joints, causing arthritis. When it affects the facial bones, it can cause dental problems. Because of changes to the bone, pagetic bones often contain more blood vessels than normal, increasing blood flow to affected bones. Because the heart has to work harder to pump the extra blood, Paget's patients with heart disease may be at even greater risk for heart failure. Paget's disease is rarely fatal.