Paget's disease of the bone occurs when bones become too large and weak due to an error in the normal process of bone breakdown and rebuilding. The disease may affect any bone in the body, but it often tends to affect the bones of the pelvis (the area between the stomach and thighs) and legs. It may also affect the skull, lower spine and sacrum (the tail bone).
Paget's disease rarely spreads from one site to another. If the disease is in the pelvis, it's not likely to affect the spine or skull. Paget’s generally "burns out" in time, causing no additional pain or damage. Any damage the disease has already caused, however, is irreversible.
Paget's disease is rarely life threatening, but it can lead to fractures and other problems if not treated properly. In very rare cases, Paget's can transform into a life-threatening cancerous bone disease.
About one million people in the United States have Paget's disease. The disease is more common in older people and those of Northern European descent. Men are more likely than women to have the disease.
The cause of Paget’s disease is unknown. Doctors think a virus may cause Paget’s disease in some cases. In other cases, it seems to be passed down by parents. But most people do not have any family members with it.
The symptoms of Paget’s disease include:
- Enlarged bones
- Broken bones
- Damaged cartilage in joints
Bones weakened by Paget’s may break more easily. The disease may cause bowed legs or a curved spine. Over time, arthritis may develop in the hips, knees or back when enlarged. Misshapen bones put extra stress on nearby joints. Having Paget’s in the skull may cause an enlarged head, headaches and hearing loss. In severe Paget’s, heart, kidney and nervous systems may occur. However, most people with Paget’s have such mild symptoms that they are unaware they have the disease.
To diagnose Paget’s disease, the doctor will perform a physical examination, collect information on personal and family medical health history and order blood tests and bone X-rays.
The goal of treatment is to relieve pain and slow down the progression of the disease. There are two types of drugs for Paget’s disease. Bisphosphonates are most commonly used. These drug help to slow down the process of bone turnover. Calcitonin may be used for some patients, but does not work as well as bisphosphonates. If there is joint damage and resulting pain is a problem, joint replacement may be needed.
There are two types of doctors who are the most experienced in treating patients with Paget’s disease:
- Endocrinologists, who treat metabolic conditions
- Rheumatologists, who treat arthritis and other muscle conditions
Depending on how the disease affects the body, the healthcare team may also include one or more of the following specialists:
- Orthapaedists, who treat bone conditions
- Neurologists, who treat brain and nerve problems
- Otolaryngologists, who treat hearing problems
Taking a proactive role in treatment – a process called self management – is important. Here are some ways to help manage the disease:
Develop and maintain strong bones. To maintain strong bones, you should get 1,200 mg of calcium and at least 400 IU of vitamin D every day. After age 70, you should take 600 IU of vitamin D each day. If you have had kidney stones, talk with your doctor about how much calcium and vitamin D to take.
Be physically active. Exercise helps keep joints mobile and build strong bones. Talk to a doctor or a physical therapist before starting an exercise program to choose the most appropriate exercises.