“Sepsis is a clinical syndrome that complicates severe infection and is characterized by the systemic inflammatory response syndrome (SIRS), immune dysregulation, microcirculatory derangements, and end-organ dysfunction. In this syndrome, tissues remote from the original insult display the cardinal signs of inflammation, including vasodilation, increased microvascular permeability, and leukocyte accumulation.

Although inflammation is an essential host response, the onset and progression of sepsis center upon a “dysregulation” of the normal response, usually with an increase in both proinflammatory and antiinflammatory mediators, initiating a chain of events that leads to widespread tissue injury.”

Uptodate.com (https://www.uptodate.com/contents/systemic-inflammatory-response-syndrome-sirs-and-sepsis-in-children-definitions-epidemiology-clinical-manifestations-and-diagnosis)