Exams and Tests

Most people who have Paget's disease have no symptoms. Most often Paget's disease is discovered when you see your doctor for a different reason, such as hip pain. A bone X-ray or abnormal blood test often leads to the discovery of Paget's disease.

When your doctor or nurse suspects Paget's disease, he or she usually can diagnose it based on your medical history, physical exam, bone X-rays, lab tests, and possibly a bone scan.

Your doctor or nurse will want to be sure your symptoms are not caused by bone cancer, noncancerous tumors, fibrous tissue within the bone, or soft and deformed bones.

Lab tests. Lab tests alone cannot be used to diagnose Paget's disease. Your doctor can use the results of lab tests along with results of your physical and medical exams and bone X-rays.

• Alkaline phosphatase test. The most important lab marker for Paget's disease is alkaline phosphatase, which is an enzyme produced by bone. When bone tissue grows quickly, as in Paget's disease, large amounts of alkaline phosphatase are released into the blood. Other body organs also make this enzyme, so your doctor will want to do more tests. The test for alkaline phosphatase can be used to help diagnose people who have symptoms of Paget's disease or to monitor whether the disease is active or inactive.
• Markers of bone breakdown. Both bone and cartilage contain collagen, which is released when bone tissue breaks down. Pyridinoline, deoxypyridinoline, and N-telopeptide (NTX) are fragments of collagen that may be found in urine. High levels of these substances in the urine may indicate Paget's disease. Tests for these markers may be done to monitor your response to treatment, but they are not typically used to diagnose the disease.

X-rays. Several types of X-rays may be used to confirm the diagnosis of Paget's disease and help find out whether there are complications from the disease. X-ray tests may include:

• Bone scan. This is the best test for diagnosing Paget's disease. You may have a bone scan of your entire body to find out which bones are affected. A bone scan is also useful for finding out whether Paget's disease is active or inactive and may show small breaks in bones that cannot be seen on a regular X-ray. But a number of diseases can cause an abnormal bone scan.
• Bone X-rays. X-rays of bones affected by Paget's disease show an uneven pattern of bone growth. The affected bones often look deformed and thickened.
• Magnetic resonance imaging (MRI). This test may be most useful if there are nervous system problems, such as hearing loss, vision problems, headaches, weakness or numbness of the face, or dizziness. Bone and nerves in the head affected by Paget's disease can be seen on an MRI.
• Computerized axial tomography (CAT scan). This test is most often used when bones of the skull or spine are affected by Paget's disease.

If you are diagnosed with Paget's disease, you will need regular checkups by your doctor or nurse to watch the progress of the disease. Monitoring may include blood and urine tests that measure the amount of chemicals released from bone.

Early detection

Most people are not screened for Paget's disease. But if you have a family history of this disease, you may want to talk with your doctor or nurse about having your blood tested (alkaline phosphatase test) when you reach age 40.