What is Paget's disease?

September 21, 2025 •

2 min read

Affecting up to 1 million people in the United States alone, Paget's disease of bone is a chronic disorder that disrupts your body's natural bone renewal cycle. This condition leads to bones that are weak, enlarged, and prone to fracture, though many people with the disease may not experience noticeable symptoms.

Quick Summary

Paget's disease of bone is a chronic condition causing abnormal and accelerated bone breakdown and regrowth, resulting in enlarged, misshapen, and fragile bones, most commonly affecting the pelvis, skull, spine, and legs.

Key Points

Abnormal Bone Remodeling: Paget's disease accelerates and disrupts the body's natural cycle of bone breakdown and regrowth, leading to disordered and fragile bone formation.
Weak and Deformed Bones: The resulting bone tissue is enlarged, misshapen, and significantly weaker than normal bone, increasing the risk of fractures and deformities.
Commonly Affected Areas: The disease most often impacts the spine, pelvis, skull, and legs, though it can occur in any bone.
Often Asymptomatic: Many people with Paget's disease experience no symptoms and are diagnosed by chance during tests for other conditions.
Primary Treatment with Bisphosphonates: The main treatment involves bisphosphonate medications, which help to normalize the bone remodeling process and prevent complications.
Genetic and Environmental Link: The cause is unknown, but a combination of inherited genetic factors and possible environmental triggers, like a virus, are suspected.

Understanding the Bone Renewal Cycle

Our bones are living tissues constantly being broken down and rebuilt in a balanced cycle involving osteoclasts (breaking down old bone) and osteoblasts (creating new bone). This remodeling keeps bones strong and dense.

The Disruption of Paget's Disease

Paget's disease disrupts this balance; osteoclasts become overactive, and osteoblasts produce new bone too quickly. The resulting bone is disorganized, weak, and prone to fractures, often affecting the spine, skull, pelvis, and long bones of the limbs.

Causes and Risk Factors

The exact cause is unknown, but a combination of genetic and environmental factors is suspected. Genetic predisposition plays a role, with several linked genes, and some research points to a potential viral trigger. The disease is more common in those over 50 and of Northern European descent.

Common Symptoms and Complications

Many with Paget's disease are asymptomatic. When symptoms occur, they include bone or joint pain, bone deformities, fractures, and neurological issues due to nerve compression if the skull or spine is affected. Other complications can include increased head size and osteoarthritis.

Diagnosis and Testing

Diagnosis involves X-rays showing bone changes, blood tests indicating high alkaline phosphatase levels, and sometimes a bone scan to identify affected areas. A biopsy may be used rarely to confirm the diagnosis.

Treatment Options

Treatment focuses on managing symptoms and preventing complications. Bisphosphonates are the primary medication to slow bone turnover. Pain relievers can manage discomfort. Surgery may be needed for deformities, joint damage, or nerve compression. A healthy diet with calcium and vitamin D, plus gentle exercise, supports bone health.

Comparing Paget's Disease with Osteoporosis

Both are bone disorders but affect bone differently:


Feature	Paget's Disease of Bone	Osteoporosis
Effect on Bone	Enlarged, misshapen, dense, but weak bone.	Generalized loss of bone mass and density.
Affected Areas	Specific areas, often pelvis, skull, spine, legs.	Entire skeleton, fractures in spine, hip, wrist most common.
Symptoms	Often asymptomatic; can cause pain, deformities, nerve issues.	Often asymptomatic until fracture; can cause back pain, height loss.
Primary Cause	Unknown; genetics, environment suspected.	Aging, hormonal changes, nutrient deficiencies.

Living with Paget's Disease

Most individuals can live active lives with proper management, including regular medical monitoring, physical therapy, and assistive devices. Paget's disease of bone is distinct from other conditions with similar names, such as Paget's disease of the breast. Always consult a healthcare professional for accurate diagnosis.

For additional medical information, refer to reputable health resources.

Conclusion

Paget's disease of bone is a chronic condition characterized by abnormal bone remodeling, leading to weakened and misshapen bones. While often asymptomatic, it can cause pain, fractures, and nerve compression. Treatment with bisphosphonates helps manage the disease and maintain a good quality of life. Early diagnosis and consistent medical care are vital.

Frequently Asked Questions

The exact cause is unknown, but it is believed to be a combination of genetic predisposition and possible environmental factors, such as a slow-acting virus, which may trigger the disease in susceptible individuals.

Many people have no symptoms. When they do occur, common symptoms include bone or joint pain, headaches, hearing loss, and bone deformities like bowed legs or an enlarged skull.

No, there is currently no cure for Paget's disease. However, treatments, primarily bisphosphonate medications, can effectively manage symptoms and slow the disease's progression.

No, Paget's disease of bone is not a cancer. However, in very rare cases, the condition can lead to a type of bone cancer called osteosarcoma.

Diagnosis typically involves a combination of tests, including X-rays, blood tests (checking for elevated alkaline phosphatase), and sometimes a bone scan to identify all affected areas.

No, Paget's disease does not spread from one bone to another. It can affect a single bone or multiple bones, but the disease only progresses within the bones that are already affected.

Risk factors include being over 50 years old, male, and of Northern European descent. Having a family history of the disease also significantly increases one's risk.