This document defines sepsis, SIRS, and septic shock and outlines how to differentiate between them. SIRS is defined as having two or more symptoms of infection like fever or elevated heart rate. Sepsis occurs when SIRS is present with a confirmed infection. Septic shock is severe sepsis plus hypotension or need for vasopressors. The document discusses how infection can propagate to sepsis if factors like immune status or treatment delay are present. It also provides the Sequential Organ Failure Assessment (SOFA) score to assess sepsis severity and emphasizes the need for early antibiotic administration in suspected sepsis to improve outcomes.