Paget's disease disrupts the normal cycle of bone renewal and repair, causing bones to become weakened and deformed.
Bone pain is the most common symptom of Paget's disease, often affecting the pelvis or spine. The pain is usually worse when lying down.
You should visit your GP if you experience bone pain or notice any bone deformities.
However, in many cases of Paget's disease there are no noticeable symptoms, and it is only diagnosed during tests for an unrelated medical condition or when a bone is fractured.
Read more about the symptoms of Paget's disease and diagnosing Paget's disease.
Why does Paget's disease happen?
Paget's disease is caused by a problem with the process of bone renewal that results in bone being replaced at a faster rate than usual. This leads to enlarged bones that are weak and brittle.
It is not clear why this happens, but both genetic and environmental factors are believed to be important. In around 15% of cases there is a family history of the condition.
Read more about the causes of Paget's disease.
Treating Paget's disease
The condition is not usually treated immediately if Paget's disease is not causing any symptoms, although your health will be regularly monitored.
There is no cure for Paget's disease. Treatment can help relieve symptoms and prevent the condition getting worse.
Medication can help control bone regeneration, with a type of medicine called bisphosphonates being the first choice. These are taken as a tablet or injection.
Over-the-counter painkillers such as paracetamol and ibuprofen can relieve pain.
Surgery is only used if Paget's disease causes further problems, such as osteoarthritis or a bone fracture.
Read more about treating Paget's disease.
Complications of Paget's disease are uncommon, but can be potentially serious. They include bone deformities, hearing loss and osteoarthritis.
In very rare cases, Paget's disease can cause heart failure or bone cancer.
Read more about complications of Paget's disease.
Who is affected?
After osteoporosis, Paget's disease is the second most common type of bone disease in the UK, although the number of cases is declining.
The UK has the highest rates of Paget's disease in the world and it is relatively common in countries where there have been high levels of migration from Britain, such as Australia, New Zealand and South Africa.
It most often occurs in people of white British descent and is very rare among other ethnic groups.
Paget's disease is also an age-related condition, rarely affecting young people. It is estimated about 2% of white adults aged over 55 have the condition in the UK.