Paget’s disease of bone is a chronic disorder characterized by abnormal bone remodeling, leading to enlarged, weakened, and deformed bones. It primarily affects older adults and is caused by excessive bone resorption by osteoclasts followed by disorganized bone formation by osteoblasts. The exact cause is unknown, but genetic factors (e.g., SQSTM1 gene mutations) and possible viral triggers (e.g., measles virus) are implicated.
Key Features:
Symptoms: Often asymptomatic, but may include bone pain, joint pain, deformities (e.g., bowed legs, skull enlargement), fractures, and nerve compression (e.g., hearing loss if the skull is affected).

Common Sites: Pelvis, spine, skull, femur, and tibia.

Complications: Osteoarthritis, fractures, heart failure (due to increased blood flow to affected bones), and, rarely, osteosarcoma (bone cancer).

Diagnosis:
Imaging: X-rays show characteristic bone enlargement, thickening, and sclerosis. Bone scans detect areas of high bone turnover.

Lab Tests: Elevated serum alkaline phosphatase (ALP) indicates increased bone formation. Normal calcium and phosphate levels are typical unless immobilized.

Biopsy: Rarely needed but can confirm disorganized bone structure.

Treatment:
Medications:
Bisphosphonates (e.g., alendronate, zoledronic acid): First-line to reduce bone turnover and relieve pain.

Calcitonin: Less common, used if bisphosphonates are not tolerated.

Supportive Care: Pain management (e.g., NSAIDs), physical therapy, or surgical intervention (e.g., for fractures or severe deformities).

Monitoring: Regular imaging and ALP levels to assess disease activity.

Epidemiology:
More common in people of European descent, rare in Asian and African populations.

Prevalence increases with age; affects ~2-3% of people over 55 in Western countries.

Slight male predominance.

Prognosis:
Most patients manage well with treatment, but the disease is chronic and may progress.

Complications like osteosarcoma are rare (<1%) but serious.

Disclaimer: owerl is not a doctor; please consult one.