What Is Paget's Disease of Bone and How Does It Affect You?
Paget's disease of bone is a long-term condition where the normal cycle of bone breakdown and renewal goes wrong. Affected bones become thicker, weaker and sometimes misshapen. It most often appears in the pelvis, spine and legs of adults over 50, and many people have no symptoms at all. Blood tests and bone scans are the main tools used for diagnosis.
Key takeaways
- Paget's disease causes abnormal bone remodelling, making bones thicker but structurally weaker.
- It is often discovered by chance on an X-ray or blood test, with no symptoms present.
- Diagnosis relies on blood tests (raised alkaline phosphatase) and bone scans, not standing imaging alone.
- If Paget's changes the shape of your pelvis, spine or legs, a standing assessment can show how your alignment has been affected.
- Treatment, when needed, is managed by a rheumatologist or specialist, usually with medication called bisphosphonates.
You may have been told you have Paget's disease after routine blood work turned up a raised alkaline phosphatase level, or after an X-ray taken for something else showed thickened bone. Either way, the name can sound alarming. Understanding what is actually happening inside the bone helps you make sense of any next steps your doctor recommends.
What are the symptoms of Paget's disease of bone?
Many people with Paget's disease have no symptoms at all. When symptoms do appear, they tend to develop slowly over months or years and depend on which bone is affected.
When to seek urgent help. If you develop sudden numbness, weakness in your legs, or loss of bladder or bowel control, contact your GP, call 111 or go to A&E straight away. These could signal nerve compression that needs immediate attention.
What causes Paget's disease of bone?
The exact cause is not fully understood. Current evidence points to a combination of genetic and environmental factors that disrupt the body's normal bone remodelling cycle.
It is worth noting that Paget's disease is separate from osteomalacia, which is a softening of bone due to vitamin D deficiency. Both can cause bone pain in older adults, but the underlying problem, diagnosis and management are quite different.
How is Paget's disease of bone diagnosed?
Diagnosis usually relies on blood tests and a bone scan, not standard imaging alone. Many cases are found by accident when a blood test shows a raised alkaline phosphatase level or when thickened bone appears on an X-ray taken for another reason.
The key diagnostic tools
- Blood test. Alkaline phosphatase (ALP) is an enzyme released during bone remodelling. A raised ALP level alongside normal liver function is a strong pointer toward Paget's disease.
- Bone scan (radionuclide scan). A small amount of tracer is injected into a vein and collects in areas of active bone turnover. This highlights exactly which bones are affected.
- X-ray. X-rays can show characteristic changes such as thickened trabeculae (the internal struts of bone), enlarged bone, or areas where bone density looks patchy. However, an X-ray alone does not confirm Paget's disease in every case.
Your GP will usually arrange the blood test and, if the results suggest Paget's, refer you to a rheumatologist or metabolic bone specialist for confirmation and a management plan.
A note on imaging choices. EOS and standard X-rays show bones, joints and alignment well. For soft tissue, discs or nerves, MRI is usually the better tool. If your specialist suspects nerve compression caused by thickened bone, they may request an MRI alongside other tests.
How does Paget's disease affect your posture and alignment?
When Paget's disease changes the shape of a weight-bearing bone, it can shift the way your whole body lines up when you stand. A bowed thigh bone, for example, tilts the pelvis. The spine then curves to compensate. Over time, you may develop pain in your back or hip that is actually caused by the alignment shift, not by the Paget's itself.
This is where the distinction between lying-down imaging and standing imaging matters. When you lie on a table for a standard X-ray, CT or MRI, gravity is removed and your muscles relax. The image may miss the tilt or curve that appears the moment you stand up and bear weight. A full, standing image of the skeleton from head to foot shows the complete chain of compensation.
If you have a confirmed diagnosis of Paget's disease and your specialist wants to understand how it has changed your alignment, ScanAlign standing EOS imaging captures the full picture in one low-dose exposure, with about 90% less radiation than a standard X-ray, around ten times less. This does not diagnose Paget's disease itself. Blood tests and bone scans do that. But it can reveal the downstream alignment effects that help guide decisions about bracing, joint replacement planning or physiotherapy.
If you already have a Paget's diagnosis and want to understand how it has affected your alignment, you can book a standing assessment or start with a free video consultation to discuss whether it is the right step.
Book a free video consultationWhat helps manage Paget's disease of bone?
Not everyone with Paget's disease needs treatment. If the condition is not causing pain or affecting a critical bone, your specialist may recommend monitoring with regular blood tests to track alkaline phosphatase levels.
When treatment is needed
If you have bone pain, involvement of a weight-bearing bone, or changes near a joint, your rheumatologist will usually consider medication. Bisphosphonates are the most common choice. These drugs slow down the overactive bone cells, allowing healthier bone to form. They are typically given as a short course of tablets or a single intravenous infusion.
Ongoing monitoring
After treatment, your specialist will check your alkaline phosphatase level periodically. A falling level usually means the medication is working. Most people do not need repeated courses, but some do if their levels rise again over the years.
Supporting your body day to day
- Stay active within comfort. Gentle, regular movement helps keep joints mobile and muscles strong around affected bones.
- Maintain adequate calcium and vitamin D through diet and, if advised, supplements. Your specialist will guide you.
- Use appropriate pain relief as discussed with your GP or specialist.
ScanAlign is a diagnostic imaging clinic and does not provide treatment. If you need a clearer picture of how Paget's has changed your skeletal alignment, imaging can inform the treatment plan your specialist creates for you.
Frequently asked questions about Paget's disease of bone
No. Paget's disease is a benign condition of abnormal bone remodelling. In very rare cases, a bone affected by long-standing Paget's can develop a type of bone cancer called osteosarcoma, but this is uncommon. Your specialist will monitor you if there are any concerns.
Alkaline phosphatase is an enzyme involved in bone and liver activity. A raised level with normal liver function often points to increased bone turnover. Paget's disease is one of the most common causes, but your doctor will rule out other possibilities first.
Yes. If Paget's affects a vertebra in your spine, the thickened bone can press on nerves or change the shape of the spine, leading to back pain and stiffness. Alignment changes from a bowed leg or tilted pelvis can also create secondary back pain.
Usually, yes. Your specialist will typically request a bone scan to identify which bones are involved. X-rays of the affected areas may follow. These tests guide decisions about whether treatment is needed.
EOS imaging is not the primary tool for diagnosing Paget's disease. Blood tests and bone scans do that. However, if you already have a diagnosis and your specialist wants to see how bone changes have affected your standing alignment, an EOS scan can provide that full-body picture.
An EOS scan uses about 90% less radiation than a standard X-ray, around ten times less. This makes it a very low-dose option when your specialist needs a full standing image of your skeleton.
It can be. Having a close relative with Paget's disease increases your risk. Researchers have identified several genes linked to the condition, though not everyone with those genes will develop it.
No referral is required. ScanAlign is a private self-pay clinic, and you can self-refer. However, for Paget's disease specifically, the primary diagnostic tests (blood work and bone scans) are best arranged through your GP or specialist first. Standing alignment imaging is most useful once the diagnosis is confirmed.
For up-to-date pricing and what is included, please visit the ScanAlign FAQs and cost page.
Both conditions affect bone and can cause pain, but the underlying problem is different. Paget's disease involves overactive bone remodelling producing disorganised bone. Osteomalacia is caused by a lack of vitamin D, leading to soft, undermineralised bone. The tests and treatments for each are distinct.
Want to understand how Paget's has changed your alignment?
If you already have a diagnosis and want to see the bigger picture, start with a free video consultation. We will help you decide if a standing assessment is the right next step.
Book a free video consultationWritten by Abbas Dhami (Specialist Diagnostic Radiographer)
Sources
- NHS. "Paget's disease of bone." nhs.uk. Available at: https://www.nhs.uk/conditions/pagets-disease-bone/
- Ralston SH et al. "Diagnosis and management of Paget's disease of bone in adults: a clinical guideline." Journal of Bone and Mineral Research, 2019; 34(4):579-604.
- Paget's Association UK. Patient information resources. Available at: https://paget.org.uk/
This page is general information and not a diagnosis.
ScanAlign is the trading name of CoreMed Solutions Ltd and operates under The Harley Street Hospital's CQC licence.