Paget's Disease

The information in each section below explains what Paget's disease is, how it is diagnosed and discusses causes, symptoms and complications. See the Treatment section for information on the treatment and interventions which may be used.

What is Paget's disease of bone?

Paget’s disease is a metabolic bone disorder in which the normal repair and renewal process within bone is disrupted.

Paget’s disease often causes no symptoms and may be found by chance. For those with symptoms these may include pain, deformity and fracture. Occurring more commonly with advancing age, Paget’s disease rarely occurs in those under 50. In the UK, it presents in approximately 8% of men and 5% of women, by the age of 80 years. Either single or multiple bones may be affected with common sites being the spine, skull, pelvis and thigh (femur).

How does Paget’s disease affect bone?

Bone is an active living tissue that is constantly being renewed through a process known as remodelling. Cells called osteoclasts break down old, damaged bone to make way for new bone laid down by cells called osteoblasts. Over time, this bone is mineralised, forming a hard and strong skeleton. Under normal circumstances the amount of bone removed is balanced by the amount of bone laid down. In Paget’s disease the osteoclasts are larger than usual and break down bone more rapidly. The osteoblasts respond to this by depositing new bone at an increased rate. This activity leads to an increase in bone size which has an irregular and weakened structure.

You can watch a video of bone remodelling and Paget's disease by following this link to an external website

What causes Paget’s disease?

There are still some uncertainties about the causes of Paget’s disease but there is a general understanding that it is due to a combination of inherited and environmental influences.
It is unclear why only certain bones are affected. This may be related to mechanical stresses that are placed on the skeleton at specific sites or differences in the blood supply to these bones. For more information see our Fact's Booklet and Newsletters which are all available in the Member's Area of this website: log-in or register.

What are the symptoms?

In many cases there may be no symptoms and individuals are unaware that they have Paget’s disease. It may be discovered by chance on x-ray or if a blood test is performed for another reason.
Some patients will present with symptoms, of which pain is the most common. Deformity can sometimes be apparent. For instance, long standing disease over many years, may cause the weight bearing bones of the leg to develop a bowing deformity (see complications).

Further information can be found in our Booklets and Newsletters in the Member's Area of this website.

How is Paget’s disease diagnosed?
  1. A simple blood test which can be carried out by your GP may show an increased alkaline phosphatase (ALP) level. This could indicate Paget’s disease. A rise in ALP can indicate other conditions so this test is not used in isolation.

    - The ALP can be normal even if Paget's Disease is active - this can happen when Paget's is active in a small area of bone.

    - Active Paget's disease can sometimes be seen as a gradual rise of the ALP within normal limits.

  2. Paget's disease can be seen on a plain x-ray of the affected bone.

  3. An Isotope Bone Scan is used to determine the extent and activity of the disease. Download information sheet (PDF): Isotope Bone Scans

  4. There may be a family history of Paget's Disease.

  5.  A full assessment by a hospital consultant is recommended to determine if treatment is required.

Log-in to read Professor Fraser's article on Blood tests in Paget’s Disease of Bone, which you will find under Information in the Member's Area.


What are the possible complications?
Possible complications of Paget's Disease:
  • Fracture: A predisposition to fracture in affected bones, particularly the long bones of the arm and leg. 
    Enlarged, misshapen bone. For example: if a long bone, such as in the lower leg is affected, it can become bowed (see photo below).
  •  "Bone Deformity in Paget’s Disease"  an article by Dr D. Hosking can be found in our Member's Area. The photos below shoe examples of deformity in the arm and the lower leg due to Paget's disease.

Bowed legDeformity of the arm

Examples of complications arising from the involvement of specific bones:
  • Skull. Paget's in the skull can cause headaches, hearing loss, ringing in the ears and a change in shape and / or size of the skull (i.e. enlarged head, wide forehead).
  • Spine. Paget's in the spine can lead the affected vertebrae to become enlarged and deformed which can cause curvature of the spine, pain, and pressure on nerve roots with tingling, weakness and numbness in the legs. 
  • Femur. Paget's in the femur (thigh) can cause local pain at the site of the Paget's disease or related to osteoarthritis of the hip joint. Fissure (partial) fractures in the bone may lead to a complete fracture.
  • Pelvis. Paget's in the pelvis may be painful and accelerate osteoarthritis in the hip joint.
  • Shin. When the lower leg is affected the bone may feel warm, be painful and it may bow. Osteoarthritis may develop in the knee joint and fissure fractures may occur possibly leading to complete fracture.
Paget's Disease and Osteoarthritis

Paget’s disease is associated with an increased risk of developing osteoarthritis. Deformity or enlargement of a bone can place increased stress on an adjacent joint which can lead to excess wear and tear. You can read an article by Dr S. Tuck,"Paget's and Osteoarthritis"  in our Member's Area.

Paget’s Disease of Bone-associated Osteosarcoma

This is a very rare complication of Paget’s disease. Please login to the member area to read an article by experts in Norwich and read about Allan Reid who developed this rare condition. You can also contact our nurse helpline: [email protected] 0161 7994646 or 07713568197. The Bone Cancer Research trust also has information on their website.