Adverse reactions refer to unintended and harmful effects that occur as a result of medical treatment, medication, or exposure to a substance. These reactions can vary in severity and may range from mild side effects to life-threatening conditions. Adverse reactions are an important consideration in healthcare, as they can impact patient safety, treatment effectiveness, and overall health outcomes. Research in this area focuses on understanding the underlying mechanisms of adverse reactions, identifying risk factors, and developing strategies to prevent and manage these events. This research is crucial for improving patient care and minimizing the potential harm associated with medical interventions.