What is Paget's disease of bone?

Paget's disease is a problem of abnormal bone growth. It may affect just one bone, but it usually affects more than one.

• In normal bone, the bone tissue is constantly being broken down, absorbed into the body, and then rebuilt with new cells.
• In Paget's disease, bone tissue is broken down and absorbed much faster than normal, so the body speeds up the bone rebuilding process. But this new bone is often weak and brittle, and it breaks easily.

Paget's disease is most common in people older than 50, and the risk of getting it increases with age. Most people who have it are able to lead normal lives.

What causes it?

The cause of Paget's disease is not clear. But it may be related to:

• Genetics. You're more likely to get Paget's disease if your parents, brothers, or sisters have it.
• Viruses. The viruses linked to measles in people and distemper in dogs have been found in the bones of people with Paget's disease. But there's no proof that these viruses cause this disease.

What are the symptoms?

Most people with Paget's disease have no symptoms. When symptoms occur, the most common ones are:

• Bone pain. It may be worse at night and get better with exercise. People often mistake the pain for normal aging or arthritis.
• Deformed bones, such as bowed legs, an enlarged skull or hips, or a curved backbone.
• Broken bones, or fractures.

Other symptoms may occur, depending on which part of the body is affected by Paget's disease.

• If it affects the skull, you may have symptoms such as headaches, sagging face muscles (facial droop), hearing problems, or loose teeth.
• If it affects the spine, it may damage nerves and cause leg pain, numbness, or weakness. It can also cause an emergency condition called cauda equina syndrome that results in loss of feeling in the pelvic area and legs.

How is it diagnosed?

Paget's disease is most often found by chance when a person sees a doctor for a problem such as hip or back pain. An abnormal X-ray or blood test may lead the doctor to discover this disease.

To diagnose Paget's disease, the doctor will ask about your past health, do a physical exam, and order tests such as:

• Bone X-rays. Affected bones often look deformed and too thick on X-rays.
• Bone scan. This is the best test for diagnosing Paget's disease. You may have a bone scan of your whole body to find out which bones are affected.
• Blood and urine tests. The most important one for diagnosing Paget's disease is a blood test for alkaline phosphatase, an enzyme made by bone. If the level of this enzyme is high, your doctor will want to do other tests.

You might also need other tests, such as an MRI or a CT scan.

How is Paget's disease of bone treated?

Many people don't need treatment for Paget's disease. But even if you don't need treatment, you will still need to see your doctor on a regular basis from now on. This will let your doctor watch for other problems you might get from the disease, such as arthritis, fractures, or nerve problems.

Your doctor may prescribe medicine if you have symptoms or if you have no symptoms but you are at risk for other problems from Paget's disease. Medicine can help reduce the breakdown of bone tissue, control symptoms such as bone pain, and prevent other problems such as arthritis, fractures, or nerve damage.

Bisphosphonates are usually the first medicines prescribed for Paget's disease. They often make the disease inactive, sometimes for years or decades. If it becomes active again, you may need to take this medicine off and on to keep the disease under control.

If you still have pain while taking your prescribed medicine, you can try:

• An over-the-counter pain reliever such as acetaminophen, naproxen, or ibuprofen. Be safe with medicines. Read and follow all instructions on the label.
• Acupuncture or relaxation techniques such as guided imagery or biofeedback.

You might also need other treatments, such as:

• Physical therapy to build your muscles and improve your balance. This can help reduce falls and prevent broken bones.
• Splints or braces to support your bones and joints and to help keep weak bones from breaking.
• A cane or walker to help you avoid falling and breaking a bone.
• A hearing aid if the disease has caused hearing loss.

Some people may need surgery to replace a damaged hip or knee joint.

How can you care for yourself?

There are many things you can do to help yourself when you have Paget's disease.

• Learn ways to manage your pain. For example, you might keep a pain diary to find out what makes your pain better or worse.
• Take care to avoid falls. For example, keep your home's walkways free of clutter and electric cords. Put grab bars in your bathroom.
• Do weight-bearing exercise to keep your bones strong. Walking, dancing, or lifting weights may be good, but make sure that you don't put stress on affected bones. Your doctor or physical therapist can suggest exercises for you.
• Eat a healthy diet that includes plenty of calcium and vitamin D. You need both to build strong bones.