Osteoporosis

Osteoporosis is a skeletal disorder characterized by low bone mass and deterioration of bone tissue, resulting in fragile bones and a higher risk of fracture. Bone strength reflects density and quality; in osteoporosis, bone remodeling is imbalanced, increasing fracture risk at the hip, spine, and wrist even after minor trauma.

It is most common in older adults, especially postmenopausal women, but also affects men and people with secondary risk factors. Key risks include aging, female sex, low body weight, smoking, excessive alcohol, inadequate calcium or vitamin D, sedentary lifestyle, and use of glucocorticoids or certain other medications, as well as chronic diseases.

Pathophysiology involves greater bone resorption than formation, leading to thinning of trabecular and cortical bone and poorer microarchitecture.

Diagnosis is typically by dual-energy X-ray absorptiometry (DXA). A T-score of −2.5 or lower defines osteoporosis; between −1.0 and −2.5 is osteopenia. Z-scores apply to younger individuals. Fracture risk tools like FRAX help guide treatment decisions.

Prevention and treatment emphasize lifestyle and medications. Adequate calcium and vitamin D, weight-bearing and resistance exercise, and avoiding smoking and excess alcohol are advised. Pharmacologic options include bisphosphonates (eg, alendronate), denosumab, and anabolic agents such as teriparatide or romosozumab, chosen based on risk and comorbidity. Ongoing monitoring with DXA is common.

With appropriate management, fracture risk can be reduced and quality of life preserved.