Drug hypersensitivity is a research field and clinical concept dedicated to the comprehensive study of adverse drug reactions that phenotypically resemble allergic responses. This domain investigates the diverse underlying immunological and non-immunological mechanisms, clinical manifestations, classification systems (e.g., immediate vs. non-immediate, allergic vs. non-allergic), diagnostic methodologies, risk factors, and management strategies associated with these reactions. Characterized by a wide spectrum of clinical presentations and varying temporal onset, its significance is underscored by its critical role in enhancing patient safety, minimizing morbidity and mortality, optimizing therapeutic outcomes, and reducing healthcare burdens arising from these potentially severe adverse drug effects.