Overview

Paget's disease of bone disrupts the normal cycle of bone renewal, causing bones to become weakened and possibly deformed.

It's a fairly common condition in the UK, particularly in older people. It's rare in people under 50 years of age.

There are treatments that can help keep it under control for many years, but it can cause persistent pain and a range of other problems in some people.

Symptoms of Paget's disease of bone

Paget's disease of bone can affect 1 or several bones. Commonly affected areas include the pelvis, spine and skull.

Symptoms can include:

• bone or joint pain
• skin feeling warm over the affected bone
• changes in bone shape
• a shooting pain that travels along or across the body, numbness and tingling (peripheral neuropathy), or balance problems

But in many cases there are no symptoms and the condition is only found during tests carried out for another reason.

When to see your GP

See your GP if you have:

• persistent bone or joint pain
• deformities in any of your bones
• symptoms of a nerve problem, such as numbness, tingling or balance problems

Your GP can organise tests to check your bones and look for problems such as Paget's disease of bone.

Causes of Paget's disease of bone

Bone cells regenerate in a similar way to skin – old bone is removed and replaced by new bone. This is known as bone remodelling.

2 cells are responsible for this:

• osteoclasts – cells that absorb old bone
• osteoblasts – cells that make new bone

In Paget's disease of bone, something goes wrong with the osteoclast cells and they start to absorb bone at a much faster rate than usual.

The osteoblasts then try to produce new bone more quickly, but the new bone is larger and weaker than normal.

It's not clear what triggers this, but you're at a higher risk if you have a family history of Paget's disease of bone. You may inherit a genetic fault that means you're much more likely to develop the condition.

Treatments for Paget's disease of bone

There's currently no cure for Paget's disease of bone, but treatment can help relieve the symptoms.

If you don't have any symptoms, your doctor may suggest keeping an eye on your condition and delaying treatment until any problems occur.

The main treatments are:

• bisphosphonate medication – medicines that help control bone regeneration
• supportive therapies – including physiotherapy, occupational therapy and devices such as walking sticks or shoe inserts
• surgery – this may be needed if further problems develop, such as fractures, deformities or severe joint damage

Ensuring you get enough calcium and vitamin D can also help. Some people may need to take supplements.

Further problems caused by Paget's disease of bone

Paget's disease of bone can sometimes lead to further, potentially serious problems.

These include:

• fragile bones that break more easily than normal
• osteoarthritis, which causes painful and stiff joints
• enlarged or misshapen bones
• permanent hearing loss (if the skull is affected)
• heart problems
• in rare cases, bone cancer

Other types of Paget's disease

There are several other types of Paget's diase that are not related to Paget's disease of bone.

These include:

• Paget's disease of the breast or nipple – a rare type of breast cancer
• Paget's disease of the penis – a rare type of penile cancer
• Paget's disease of the vulva – a rare type of vulval cancer

The general term "Paget's disease" is sometimes used to refer to Paget's disease of bone.

Symptoms

Symptoms of Paget's disease of bone include bone pain or joint pain and problems caused by a nerve being squashed or damaged.

But in many cases, there are no obvious symptoms and the condition is only found during tests carried out for another reason.

1 bone or several bones may be affected. Commonly affected areas include the:

• pelvis
• spine
• skull
• shoulders
• legs

Bone or joint pain

Paget's disease may cause pain in the bone itself and in the joints near the affected bone.

The bone pain is usually:

• dull or aching
• deep within the affected part of the body
• constant
• worse at night

The affected area may also feel warm.

Nerve problems

Abnormal bone growth can result in bone squashing (compressing) or damaging a nearby nerve.

Possible signs of this can include:

• pain travelling from the spine down into your legs (sciatica)
• numbness or tingling in the affected limbs (peripheral neuropathy) 
• partial loss of movement in your limbs
• balance problems
• loss of bowel control (bowel incontinence) or loss of bladder control (urinary incontinence)

Call 999 or go to A&E if you have partial loss of movement in your limbs or loss of bowel or bladder control.

Other problems

Paget's disease of bone can also cause a range of other problems, including:

• fragile bones that are more likely to break
• osteoarthritis - damage to the joints, causing painful and stiff joints
• deformities in affected bones, such as curved legs (bow legs) or a curved spine (scoliosis)
• hearing loss, headaches, vertigo (a spinning sensation) and tinnitus (hearing noises in your ears) – these may occur if the skull is affected
• heart problems

When to see a GP

See a GP if you have:

• persistent bone or joint pain
• deformities in any of your bones
• symptoms of a nerve problem, such as numbness, tingling or balance problems

A GP can organise tests to check your bones and look for problems such as Paget's disease of bone.

Diagnosis

Paget's disease of bone can be diagnosed with a blood test and an X-ray or scan.

Blood test

A simple blood test can be carried out to check the level of a substance called alkaline phosphatase (ALP) in your blood.

People with Paget's disease of bone often have raised levels of ALP, although some people with the condition have a normal ALP level and a high level can also be caused by some other conditions.

An X-ray or scan is therefore also needed to confirm the diagnosis.

X-ray and bone scan

An X-ray can show whether your bones have become enlarged as a result of Paget's disease of bone.

Sometimes a bone scan called scintigraphy may also be carried out to check how much of your body is affected by the condition.

For this scan, a small amount of a radioactive substance is injected into your blood. This collects in areas where there's a lot of bone renewal taking place.

A gamma camera is then used to detect the radiation and highlight affected parts of the body.

Further tests

Further tests are usually only needed if your diagnosis is not clear, or if you may have complications.

In these cases, you may be advised to have a:

• bone biopsy – a sample of bone is removed under anaesthetic so it can be looked at in detail
• CT scan – a series of X-rays of the affected bone are taken to create a detailed 3-dimensional image
• MRI scan – a strong magnetic field and radio waves are used to create an image of the affected bone

Treatment

There's currently no cure for Paget's disease of bone, but treatment can help relieve the symptoms.

If you do not have any symptoms, your doctor may suggest keeping an eye on your condition and delaying treatment until any problems occur.

Bisphosphonates

Bisphosphonates are medicines that help regulate bone growth. They work by affecting the cells that absorb old bone (osteoclasts).

If you need bisphosphonates you'll usually have a medicine called zoledronate. It's given as a single dose through a drip in your arm (infusion).

Zoledronate can help reduce pain for several years at a time. Treatment can be repeated when the effect starts to wear off.

Other bisphosphonates that are sometimes used include risedronate, taken as tablets, and pamidronate, given as injections.

The main side effects of zoledronate and pamidronate are flu-like symptoms that last a day or 2. The most common side effect of risedronate is an upset stomach.

Zoledronate can decrease your levels of calcium, so you'll usually be advised to take calcium and vitamin D supplements for several days after having the infusion.

If you're unable to have bisphosphonates, you may need daily injections of another medicine that prevents bone loss called calcitonin, usually for up to 3 months.

Supportive therapies

Some people with Paget's disease benefit from supportive therapies such as physiotherapy or occupational therapy.

These therapies involve exercises and techniques that can help reduce pain, improve movement and make everyday tasks easier.

Devices that reduce the weight placed on the affected bones may also help, such as:

• a walking stick or frame
• orthotics – insoles made of plastic that fit inside your shoe to help support your feet
• braces that support the spine in the correct position

Surgery

Surgery is usually only needed if further problems develop, such as fractures, deformities or severe osteoarthritis.

Operations that may be done include procedures to:

• realign the bones after a fracture so that they heal correctly
• remove and replace a damaged joint with an artificial one, such as a hip replacement or knee replacement
• cut and straighten deformed bones
• move bone away from a squashed (compressed) nerve

These operations are usually done under general anaesthetic, so you'll be asleep and will not experience any pain while they're carried out.

Diet and nutrition

Calcium and vitamin D help keep your bones healthy. If you have Paget's disease of bone, it's important to ensure you get enough of these.

You get calcium from your diet. It's found in foods such as:

• dairy foods – such as milk and cheese
• green leafy vegetables – such as broccoli and cabbage
• soya beans, soya drinks with added calcium and tofu

You get most of your vitamin D from sunlight, although it's also found in some foods such as oily fish.

Sometimes your GP may suggest taking extra calcium and/or vitamin D supplements to ensure you're getting enough.

Complications

Paget's disease of bone can sometimes lead to further problems.

Broken bones

Bones affected by Paget's disease of bone tend to be more fragile than normal bone and are more likely to break (fracture) – even after a relatively minor injury.

Signs of a fracture include:

• sudden, severe pain
• swelling or tenderness around the injured area
• bleeding, if the bone has damaged the tissue and skin 

It's not clear whether bisphosphonate medication helps prevent or treat fractures. If you break a bone, you may need surgery to align the broken bones so that they heal correctly.

Osteoarthritis

Abnormal bone growth can damage nearby cartilage, the spongy tissue that cushions your joints.

This can lead to "wear and tear" of the affected joints (also known as osteoarthritis), which can cause:

• joint pain
• joint stiffness
• swollen joints

Bone deformities

It's common for Paget's disease of bone to affect the appearance of affected bones.

For example, the condition can cause:

• enlarged or misshapen bones
• the legs to curve outwards (bow legs)
• the spine to curve to the sides (scoliosis)
• the upper back to become very hunched over (kyphosis)

As with fractures, it's not clear whether bisphosphonates can help prevent deformities. If they do occur, surgery may be carried out to correct them.

Hearing loss

If Paget's disease of bone affects the skull, there's a risk that it could lead to permanent hearing loss and possibly total deafness.

This can occur as a result of damage to the bones or nerves that connect the ears to the brain.

It's not known whether treating Paget's disease of bone helps reduce the risk of losing your hearing, but treatment is usually recommended if the condition is affecting your skull.

Heart failure

The new bone that forms in people with Paget's disease of bone often contains more blood vessels than normal bone, which can mean the heart has to work harder to pump blood around the body.

Very rarely, the heart may not be able to pump enough blood around the body. This is known as heart failure.

Symptoms of heart failure can include:

• shortness of breath
• extreme tiredness and weakness
• swelling in the legs, ankles and feet (oedema)

Heart failure can be treated with medicine and in some cases heart surgery. Read more about how heart failure is treated.

Bone cancer

Bone cancer is a rare complication of Paget's disease of bone. It's estimated to affect between 1 in 500 and 1 in 1,000 people with the condition.

Symptoms of bone cancer are similar to those of Paget's disease of bone. They can include:

• bone pain
• swelling around the affected bone
• a lump in the affected bone

Osteosarcoma is a very serious type of cancer that can spread to other parts of the body quickly. But if it's caught early enough, it may be possible to cure it by removing the affected bone.