is a detailed, in-depth analysis of one individual, a small group of individuals, or a single event or situation. In clinical research, case studies are often used to describe rare conditions, unusual presentations of disease, or novel treatments. They are typically retrospective (looking back at events) rather than prospective (observing events as they happen), which limits their ability to draw firm conclusions about the safety or efficacy of interventions. However, they can provide valuable insights, generate hypotheses, and highlight areas for further study.