This article addresses the current understanding of sepsis as one of the most critical and life-threatening conditions in modern medicine. The main causes of sepsis, its underlying pathophysiological mechanisms, and typical clinical manifestations are discussed. Sepsis is a systemic inflammatory response of the body to infection, which, if not diagnosed and treated promptly, can lead to multiple organ failure and death. Special attention is given to modern diagnostic approaches, including laboratory and instrumental methods, as well as intensive care principles such as rational antibiotic therapy, fluid resuscitation, and support of vital organ functions.