Because many people with Paget's disease do not have symptoms, the condition often is not discovered until an X-ray or blood test (called the alkaline phosphatase) obtained for other reasons suggests the disease may be present. If your doctor thinks you may have Paget's disease, specific blood and urine tests can measure the levels of certain byproducts of bone formation and breakdown. More detailed X-rays or a bone scan also may be done. In rare instances, a doctor may recommend a bone biopsy to confirm the diagnosis and exclude other possibilities. In a bone biopsy, a small piece of bone is removed with a needle so it can be examined in a laboratory.