Osteoporosis

Healthy bone is constantly remodelled. Osteoclasts remove older bone, and osteoblasts replace it. Osteoporosis develops when resorption persistently outpaces formation. The result is not simply “less calcium in the bones”; both bone mass and the internal scaffold become weaker. A normal everyday load can then produce a fragility fracture. Bone loss itself is usually painless. Many people have no symptoms until a vertebra, hip, wrist, or another vulnerable bone breaks. This is why a new symptom matters more than the patient’s description of osteoporosis as “just low bone density.” Ageing, postmenopausal oestrogen loss, long-term glucocorticoid therapy, low calcium or vitamin D intake, smoking, excess alcohol, low body weight, and limited physical activity increase risk. These factors either accelerate resorption, reduce bone formation, limit the materials needed for mineralisation, or increase the chance of falling. A previous fragility fracture or a parent with a hip fracture is especially meaningful because it signals a higher future fracture risk.