Explore the fundamentals of osteoporosis diagnosis and bisphosphonate treatment in this comprehensive physician grand rounds lecture. Delve into bone turnover processes, examine the efficacy of bisphosphonates in improving bone density and reducing fracture risk, and understand their mechanism of action. Learn about potential side effects such as atypical subtrochanteric fractures and osteonecrosis of the jaw. Investigate the concept of low peak bone mass, bone accrual, and the importance of proper timing in bone density testing. Analyze the FRAX tool for fracture risk assessment and discuss the controversies surrounding "osteopenia" diagnosis. Gain insights into bisphosphonate drug holidays, including when to consider them and their impact on bone density and fracture risk. Conclude with practical take-home points for managing osteoporosis patients and optimizing bisphosphonate therapy.