Paget's disease

Diagnosing Paget's disease

It is sometimes possible to diagnose Paget’s disease in its early stages, leading to early treatment. However, it is not yet known whether this is effective in preventing the most serious complications, such as hearing loss and bone deformity.

Serum alkaline phosphatase (SAP)

In many cases, Paget’s disease is first diagnosed during a blood test for another, unrelated condition.

This occurs because the abnormal pattern of bone remodelling caused by Paget’s disease leads to a rise in levels of a chemical called serum alkaline phosphatise (SAP) in your blood. The high levels of SAP can be detected with a blood test.

X-rays and bone scans

Paget’s disease can often be confirmed by taking X-rays of the affected bones. This can help to determine whether the bones have become enlarged due to Paget’s disease.

As well as having an X-ray, a bone scan may also be recommended. This involves having a small amount of a harmless radioactive substance injected into your blood. This substance collects in the areas of bone where there is the most activity, such as where there is abnormal bone remodelling.

A special camera, known as a gamma camera, is used to highlight where the radiation has collected. A bone scan is a useful way of pinpointing exactly where abnormal bone remodelling is taking place.

Further testing

Further testing is usually only required if:

  • You develop abnormalities that affect one or more joints.
  • You are experiencing neurological symptoms (symptoms that affect your nerves, such as pain, numbness or tingling).
  • A diagnosis of bone cancer is suspected.

In these circumstances, tests that can be used are:

  • A bone biopsy – where a sample of bone is taken under local or general anaesthetic.
  • computer tomography (CT) scan – where a series of X-rays of the affected bone are taken to show a detailed three-dimensional image.
  • magnetic resonance imaging (MRI) scan – another type of scan that uses a strong magnetic field and radio waves to build up an image of the inside of the affected bone.


Blood supplies oxygen to the body and removes carbon dioxide. It is pumped around the body by the heart.
Blood test
During a blood test, a sample of blood is taken from a vein using a needle, so it can be examined in a laboratory.
An X-ray is a painless way of producing pictures of inside the body using radiation.
Last updated: 28 December 2012

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