This learning activity examines osteoarthritis as an active, whole-joint disease rather than simple "wear and tear," tracing how its presentation, risk factors, and management shift across the adult lifespan - from post-injury OA in young athletes to multimorbid disease in older adults. It covers current epidemiology, pathophysiology, and individualized assessment, then reviews guideline-directed care per the 2019 ACR/Arthritis Foundation recommendations, including non-pharmacologic first-line strategies, appropriate use and risks of pharmacologic options, and therapies now discouraged by evidence. The activity closes by examining emerging developments - gene therapy, GLP-1 receptor agonists, and minimally invasive procedures - equipping nurses to distinguish established practice from investigational hype and counsel patients accordingly.