Overview of Paget’s Disease

Paget’s disease of bone is a chronic (long-lasting) disorder that causes bones to grow larger and become weaker than normal. The disease usually affects just one or a few bones. The bones most commonly affected by Paget’s disease include:

  • Pelvis.
  • Skull.
  • Spine.
  • Femur and tibia (leg bones).

Many people with Paget’s disease do not experience symptoms specific to the disease. However, the bone changes can cause:

  • Bone pain.
  • Misshapen bones.
  • Broken bones (fractures).
  • Inflammation and arthritis in the joints close to the affected bones.

With treatment, many people can manage their symptoms, improve pain, and control the effects of the disease.

What Happens in Paget’s Disease?

Throughout your lifetime, the body constantly removes old bone and adds new bone to the skeleton. As we age, it is normal for this process to happen at a slower pace. As the disease starts, the body loses much more bone than it makes. As Paget’s disease progresses, new bone forms at a faster rate than the rate at which old bone is removed. However, the new bone does not form correctly, leading to larger bones that are misshapen, weaker, and softer than normal bone.

Who Gets Paget’s Disease?

Certain factors may increase your risk for Paget’s disease:

  • Age. Paget’s disease is uncommon in people under age 40, and the chance of developing the disease increases as you age.
  • Anglo-Saxon descent. Paget’s disease is more common in certain geographical areas, including North America, Australia, New Zealand, and Europe in people of Anglo-Saxon descent. It is not common in Asia, Africa, and Scandinavia.
  • Family history. Paget’s disease commonly occurs in families.

Studies show that men may be slightly more likely than women to have the disease.

Symptoms of Paget’s Disease

You may not know you have Paget’s disease because many people with the disease do not have symptoms. However, fractures or misshapen bones can develop and cause pain. Sometimes, this bone pain, which is the most common symptom of the disease, is mistaken for arthritis or other disorders. Generally, symptoms develop slowly, and the disease does not spread to normal bones.

Paget’s disease can affect any bone, but usually occurs in:

  • Spine.
  • Pelvis.
  • Femur and Tibia (leg bones).
  • Skull.

In addition, some people with advanced disease may have misshapen bones and other bone changes, which may include:

  • Increase in head size.
  • Bow shape of a limb.
  • Curvature of the spine.

Other symptoms can develop, depending on the bone affected and can include:

  • Headaches and hearing loss when Paget’s disease affects the skull.
  • Tingling and numbness in arms and legs when enlarged vertebrae put pressure on the nerves in the spine.
  • Hip pain, which may occur when Paget’s disease affects the pelvis or thighbone.

Depending on the bone or bones affected by Paget’s disease, other medical problems can develop, such as:

  • Damage to joint cartilage can lead to arthritis.
  • Changes in the bones of the skull and ear can lead to hearing loss.
  • For some people who have heart disease already and severe Paget’s disease, the extra workload of pumping blood throughout the body can lead to heart failure.
  • Enlarged bones in the skull and spine can lead to pressure on the brain, spinal cord, or nerves and reduced blood flow to the brain and spinal cord.
  • When Paget’s disease affects the facial bones, the teeth may loosen. This may make chewing more difficult.
  • Rarely, people with Paget’s disease can develop bone cancer.

Causes of Paget’s Disease

Doctors do not know the cause of Paget’s disease. However, researchers suspect that environmental factors and genes play a role in the development of the disease. Scientists have identified changes in genes that may increase the chance someone could develop Paget’s disease. In addition, researchers are studying how certain viruses also may cause the disease in people who already have risk factors for Paget’s disease. Some studies suggest that, in some countries, the number of people who have Paget’s disease and the severity of the disease are decreasing.