Paget's Disease of Bone

This is the second commonest metabolic bone disease after osteoporosis, but it does seem to be becoming rarer in certain parts of the world.  Paget’s Disease of Bone (PDB) was first described by James Paget, who lent his name to several different diseases, so it is important to be aware of this if you are looking up information about your condition!  PDB is characterised by areas of bone which are more active, with evidence of both increased re-absorption of bone, and also increased bone formation.  The result is rather disorganised patches of bone, which can be warm to touch or painful, but more often cause no symptoms at all.  PDB can affect a single bone in the skeleton or multiple bones, and can affect a bone on one side of a joint but not the other.   
It is possible to tell if PDB is active by blood tests (measuring a chemical called alkaline phosphatase) or by performing special scans of the bone, called isotope bone scans.  PDB is usually perfectly obvious on plain radiographs, and is often picked up quite incidentally when patients are being examined for other conditions.  If the area of PDB is very active then the bone may very slowly change in size or shape over time, and this is one reason why PDB can cause discomfort.  
For the most part PDB is either a minor nuisance or causes no symptoms whatsoever.  Occasionally areas affected can be subject to fractures, or can cause pressure on normal structures nearby.  It is very rare for PDB to cause more serious complications, but your doctor will arrange a special investigation if this is suspected.
We do not know what causes PDB, except for a minority of patients (and their families) where there is a defined genetic cause.  However we do know how to treat the condition and areas of overactive bone can usually be controlled very easily with the same types of drugs we use in osteoporosis.  These are called bisphosphonates, which can be given either by mouth or by infusions into a vein. There are some newer treatments available but most patients respond very well to bisphosphonates, given as required.    

Other Information  

Paget Association