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Paget Disease of Bone

(Osteitis Deformans; Paget's Disease of Bone)


Julia F. Charles

, MD, PhD, Brigham and Women's Hospital

Full review/revision May 2021 | Modified Sep 2022
Topic Resources

Paget disease of bone is a chronic disorder of the skeleton in which areas of bone undergo abnormal turnover, resulting in areas of enlarged and softened bone.

  • The breakdown and formation of bone increase, resulting in bones that are thicker, but weaker, than normal.

  • Symptoms may be absent or may include bone pain, bone deformity, arthritis, and painful nerve compression.

  • X-rays show the bone abnormalities.

  • Pain and complications are treated, and bisphosphonates may be given.

Paget disease can affect any bone, but the most commonly affected bones are the pelvis, thighbone (femur), and skull. The shin (tibia), spine (vertebrae), collarbone (clavicle), and upper arm bone (humerus) are affected less commonly.

Paget disease rarely occurs in people younger than 40. In the United States, about 1% of people older than 40 have the disorder, and the prevalence increases with age. However, the prevalence of the disease seems to be decreasing. Men are 50% more likely than women to develop it. Paget disease is more common in Europe (excluding Scandinavia), Australia, and New Zealand.

Causes of Paget Disease of Bone

Normally, cells that break down old bone (osteoclasts) and cells that form new bone (osteoblasts) work in balance to maintain bone structure and integrity. In Paget disease, both osteoclasts and osteoblasts become overactive in some areas of bone, and the rate at which bone is broken down and rebuilt (called bone remodeling Bones Bones ) in these areas increases tremendously. The overactive areas enlarge but, despite being large, are structurally abnormal and weak.

The cause of Paget disease is unknown in most people. The disorder tends to run in families. Specific, identified gene abnormalities contribute in about 10% of people who have Paget disease, and other genetic abnormalities probably contribute in others. Also, some evidence suggests that a virus is involved. However, there is no evidence that the disorder is contagious.


The most common complication of Paget disease of bone is

Osteoarthritis develops in up to 50% of people and may develop in joints near the involved bone.

Fractures tend to occur more easily than normal at involved bones because these bones are weakened by Paget disease. Such fractures are called pathologic fractures.

Overgrown bone may compress nerves and other structures passing through small openings. The spinal canal may become narrow and compress the spinal cord.

Rarely, heart failure Heart Failure (HF) Heart failure is a disorder in which the heart is unable to keep up with the demands of the body, leading to reduced blood flow, back-up (congestion) of blood in the veins and lungs, and/or... read more Heart Failure (HF) develops because the increased blood flow through the affected bone puts extra stress on the heart. Because blood flow through affected bones is unusually high, those bones may bleed excessively during surgery. The affected bone becomes cancerous in less than 1% of people who have Paget disease. People whose disease progresses to bone cancer usually develop an osteosarcoma Osteosarcomas (osteogenic sarcoma) Tumors that originally start in the bone are called primary bone tumors. Primary bone tumors may be noncancerous (benign) or cancerous (malignant). After cancer is diagnosed, it is staged. Staging... read more Osteosarcomas (osteogenic sarcoma) (a cancerous bone tumor).

Symptoms of Paget Disease of Bone

Paget disease usually causes no symptoms. However, bone pain, bone enlargement, or bone deformity may occur. Bone pain may be deep, aching, and occasionally severe and may worsen at night. The enlarging bones may compress nerves, causing more pain. If osteoarthritis occurs, joints become painful and stiff.

Other symptoms vary depending on which bones are affected.

The skull may enlarge, and the brow and forehead may look more prominent (called frontal bossing). A person may notice this enlargement when a larger hat is needed. Enlarged skull bones may damage the inner ear (cochlea), which can cause hearing loss, and dizziness. The enlarged skull bones can compress nerves, which causes headaches. The veins on the scalp may bulge, possibly because of the increased blood flow through the skull bones.

Bones the upper arm, thigh, or calf may appear bowed and are more likely to break because the bone is weakened by Paget disease. The vertebrae may enlarge, collapse, or both because bones affected by Paget disease are weak. Weakened vertebrae could result in a loss of height, a hunched posture, or pinching of the nerves of the spinal cord, causing pain, numbness, or weakness.

Diagnosis of Paget Disease of Bone

  • X-rays

  • Blood tests

  • Bone scan

Paget disease is often discovered accidentally when x-rays or laboratory tests are done for other reasons. Otherwise, the diagnosis of Paget disease may be suspected based on the symptoms and a physical examination.

The diagnosis of Paget disease of bone can be confirmed by x-rays showing abnormalities characteristic of Paget disease and by a laboratory test to determine blood levels of alkaline phosphatase (an enzyme involved in bone formation), calcium, and phosphate.

Prognosis for Paget Disease of Bone

The prognosis for people with Paget disease is most often very good. However, the few people who develop bone cancer have a poor prognosis. People who develop other rare complications, such as heart failure or compression of the spinal cord, may also have a poor prognosis, unless treatment of these complications is timely and successful.

Treatment of Paget Disease of Bone

  • Treatment of pain and complications

  • Bisphosphonates

A person who has Paget disease needs treatment if the symptoms cause discomfort or if there is a significant risk or suggestion of complications, such as hearing loss, osteoarthritis, and deformity. People who do not have symptoms may not need any treatment.

Commonly used pain relievers (analgesics) such as acetaminophen and nonsteroidal anti-inflammatory drugs (NSAIDs) help reduce bone pain. If one leg becomes bowed and shortened, heel lifts can help make walking easier. Sometimes surgery is needed to relieve pinched nerves or to replace a joint that has become arthritic from Paget disease.

Bisphosphonates are drugs that inhibit bone turnover. One of several bisphosphonates—alendronate, etidronate, pamidronate, risedronate, tiludronate, or zoledronic acid—can be used to slow the progression of Paget disease. Zoledronic acid is often the bisphosphonate of choice. Except for pamidronate and zoledronic acid, which are usually given by vein (intravenously), these drugs are given by mouth. These drugs are given for the following:

  • Before orthopedic surgery to prevent or reduce bleeding during surgery

  • To treat bone pain caused by Paget disease

  • To prevent or slow the progression of complications (such as hearing loss, bone deformity, arthritis, weakness, or paralysis), especially in people who cannot have surgery

  • To people with a blood level of alkaline phosphatase twice the normal level or higher

Calcitonin is occasionally injected under the skin or into muscle. It is not as effective as the bisphosphonates and is used only when the other drugs cannot be given. Denosumab may be another alternative for people who cannot take bisphosphonates.

Doctors encourage weight bearing (such as standing and walking). Excessive bed rest (except for sleeping at night) should be avoided, if possible, to prevent hypercalcemia.

Because bone is being remodeled rapidly, people should consume adequate amounts of calcium and vitamin D in their diet. Vitamin D helps the body absorb calcium and add it to bone (a process called bone mineralization). Vitamin D and calcium supplements are often needed. Otherwise, poor bone mineralization and bone weakening (osteomalacia) may occur.

Drugs Mentioned In This Article

Generic Name Select Brand Names
7T Gummy ES, Acephen, Aceta, Actamin, Adult Pain Relief, Anacin Aspirin Free, Apra, Children's Acetaminophen, Children's Pain & Fever , Comtrex Sore Throat Relief, ED-APAP, ElixSure Fever/Pain, Feverall, Genapap, Genebs, Goody's Back & Body Pain, Infantaire, Infants' Acetaminophen, LIQUID PAIN RELIEF, Little Fevers, Little Remedies Infant Fever + Pain Reliever, Mapap, Mapap Arthritis Pain, Mapap Infants, Mapap Junior, M-PAP, Nortemp, Ofirmev, Pain & Fever , Pain and Fever , PAIN RELIEF , PAIN RELIEF Extra Strength, Panadol, PediaCare Children's Fever Reducer/Pain Reliever, PediaCare Children's Smooth Metls Fever Reducer/Pain Reliever, PediaCare Infant's Fever Reducer/Pain Reliever, Pediaphen, PHARBETOL, Plus PHARMA, Q-Pap, Q-Pap Extra Strength, Silapap, Triaminic Fever Reducer and Pain Reliever, Triaminic Infant Fever Reducer and Pain Reliever, Tylenol, Tylenol 8 Hour, Tylenol 8 Hour Arthritis Pain, Tylenol 8 Hour Muscle Aches & Pain, Tylenol Arthritis Pain, Tylenol Children's, Tylenol Children's Pain+Fever, Tylenol CrushableTablet, Tylenol Extra Strength, Tylenol Infants', Tylenol Infants Pain + Fever, Tylenol Junior Strength, Tylenol Pain + Fever, Tylenol Regular Strength, Tylenol Sore Throat, XS No Aspirin, XS Pain Reliever
Binosto, Fosamax
Actonel, Atelvia
Reclast, Zometa, Zometa Powder
Fortical , Miacalcin
Prolia, XGEVA
Calcidol, Calciferol, D3 Vitamin, DECARA, Deltalin, Dialyvite Vitamin D, Dialyvite Vitamin D3, Drisdol, D-Vita, Enfamil D-Vi-Sol, Ergo D, Fiber with Vitamin D3 Gummies Gluten-Free, Happy Sunshine Vitamin D3, MAXIMUM D3, PureMark Naturals Vitamin D, Replesta, Replesta Children's, Super Happy SUNSHINE Vitamin D3, Thera-D 2000, Thera-D 4000, Thera-D Rapid Repletion, THERA-D SPORT, UpSpring Baby Vitamin D, UpSpring Baby Vitamin D3
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