The most widely used biochemical marker to aid diagnosis of PDB is serum total alkaline phosphatase (ALP), which is typically elevated in active PDB. It should be noted that Paget's disease can be active and yet the alkaline phosphatase (ALP) may remain within the normal range, particularly if the area involved is small.
The condition has characteristic features on x-ray (summarised in Box 1). Individually, these features are not specific, but when they occur in combination, they are usually diagnostic.
Radionuclide bone scintigraphy is widely considered to be a valuable technique for the diagnosis of PDB and to assess the extent of the disease