The document discusses osteoporosis, including its definition, epidemiology, classification, etiology, risk factors, pathology, clinical manifestations, diagnosis, prevention, and treatment. Specifically, it defines osteoporosis as a condition characterized by fragile bones with low bone density and increased risk of fractures. It also notes that over 200 million people worldwide suffer from the disease, with aging populations experiencing a major increase in postmenopausal osteoporosis. Prevention focuses on lifestyle modifications like adequate nutrition, exercise, and fall prevention.