Paget's disease of bone
A chronic disorder in which the normal recycling of bone becomes overactive and disorganised, so affected bones are remodelled too fast and end up enlarged, misshapen and weaker. Many people have no symptoms; others have bone pain, deformity or fractures. It is usually treatable.
What it is
Bone is constantly renewed — old bone is removed by one set of cells and new bone laid down by another, in balance. In Paget's disease this process goes into overdrive in one or more specific areas: bone is broken down and rebuilt far too quickly and in a chaotic way, producing bone that is larger but structurally weak and prone to deformity and fracture. It usually affects older adults, tends to run in families, and most often involves the pelvis, spine, skull, thighbone and shinbone — often just one or a few bones rather than the whole skeleton. Many people have no symptoms and it is found by chance on an X-ray or from a raised alkaline phosphatase on a routine blood test. When symptoms occur they include a deep, aching bone pain, bones that look enlarged or bowed, warmth over the area, and complications depending on site — such as arthritis in a nearby joint, hearing loss if the skull is involved, nerve compression, or fracture. The hallmark blood finding is a raised alkaline phosphatase (with normal liver enzymes), reflecting the high bone turnover, and bone-specific markers help gauge activity. Diagnosis is confirmed on imaging (X-ray and a bone scan to map affected sites). Effective treatment — usually a bisphosphonate — calms the overactive bone turnover, relieves pain and helps prevent complications.
Key lab markers
- Alkaline phosphatase — the classic finding; raised, reflecting high bone turnover, with normal liver enzymes.
- Bone-specific alkaline phosphatase — a more specific measure of the bone activity, used to assess and monitor.
- P1NP and other turnover markers — raised, and followed on treatment.
- Calcium — usually normal (can rise if immobilised).
- Liver enzymes (GGT) — normal, confirming the raised ALP is from bone not liver.
Symptoms
- Often none — found by chance on an X-ray or a raised alkaline phosphatase
- Deep, aching bone pain
- Enlarged, bowed or misshapen bones; warmth over the area
- Arthritis in a joint next to an affected bone
- Hearing loss (if the skull is involved)
- Numbness or weakness from nerve compression
- Fractures through affected bone
Related lab panels
When to discuss with a doctor
Paget's disease is often silent and picked up when a routine blood test shows a raised alkaline phosphatase with normal liver enzymes, or an X-ray taken for another reason shows the typical changes. See a doctor about persistent deep bone pain, a bone that looks enlarged or bowed, new hearing loss, or unexplained fractures — especially in an older adult. It is important because effective treatment can relieve pain and prevent complications like deformity, fracture, arthritis and hearing loss. Mediora.AI can flag the characteristic pattern — a raised alkaline phosphatase and bone-turnover markers with normal liver enzymes and calcium — that suggests Paget's disease; confirming it with imaging and guiding treatment belong with your doctor.