Paget's disease of bone
Balancing bone activity
Bones are made from numerous tiny cells, which are constantly active. This is why broken bones heal. Cells called osteoclasts take old bone away while cells called osteoblasts produce new bone. Normally this activity is in a state of balance, which is why, for most of us, our skeletons stay the same size once we have stopped growing.
Sometimes the balance is upset. Overactivity of the osteoclasts produces areas of bone loss and in response the osteoblasts produce excessive amounts of new bone. This results in a condition called Paget's disease of bone.
Prevalence of Paget's disease
About one person in 25 over the age of 40 will have some degree of Paget's disease, although for most of them it will cause no problem. It is most often discovered as a chance finding when an X-ray has been taken for some other reason.
The disease does not affect all races equally. It is rare among Asians.
Symptoms of Paget's disease of bone
When Paget's disease causes problems, the main symptom is pain in the bones. The abnormal growth can cause visible deformities and sometimes (for example, if the bones of the spine are affected) nerves can be trapped, causing pains in the legs and feet. Deafness may occur because of new bone pressing on the nerve for hearing.
If there is a lot of new bone it requires increased blood supply. This can put a strain on the heart. Sometimes the skin over the site of pagetic bone feels hot.
A very rare complication, affecting less than one per cent of people with Paget’s disease, is the development of bone cancer in the abnormal bone. This complication usually only affects people who have had Paget's disease for a long time.
Treatment of Paget's disease of bone
If Paget's disease is found on an X-ray, and there are no symptoms, there is no cause for concern. It will probably not cause any trouble. For those whose Paget's is causing problems, various treatments are available which attempt to reverse the abnormal bone activity.
In the days when most men wore hats, suddenly finding that your hat was too small was often the first clue to Paget's disease. If you think the shape of your head is changing, or any of the bones in your body are changing, or if you have painful bones, ask your doctor about Paget's disease.
Last Reviewed: 06 March 2009
