sepsis

noun

sep·​sis ˈsep-səs 

plural sepses ˈsep-ˌsēz 

: a potentially life-threatening, systemic response of the immune system that results from the spread of pathogenic agents (such as bacteria or viruses) and their toxins to the bloodstream from a localized infection (as of the lungs), that involves both inflammatory and immunosuppressive activity, that is marked especially by fever, chills, rapid heart rate and breathing, fatigue, confusion, increased blood coagulation, hypotension, impaired microcirculation, and organ dysfunction, and that may progress to septic shock

Note: The primary cause of sepsis is pneumonia with secondary causes commonly including infections of the abdominal cavity and urinary tract.

compare septicemia

Examples of sepsis in a Sentence

Recent Examples on the Web

One infant receiving the Mead Johnson product died — from sepsis, the article said. —David Hilzenrath, Miami Herald, 9 Apr. 2026

Diridon, who had survived throat cancer several years ago, had been in the hospital the past two weeks after developing sepsis following a radiation treatment in January, his wife, Gloria Duffy, said. —Sal Pizarro, Mercury News, 4 Apr. 2026

The infection can sometimes spread to other body parts, including the bloodstream, and lead to sepsis. —Cara Lynn Shultz, PEOPLE, 3 Apr. 2026

One infant receiving the Mead Johnson product died — from sepsis, the article said. —David Hilzenrath, USA Today, 29 Mar. 2026

Word History

Etymology

New Latin, from Greek sēpsis decay, from sēpein to putrefy

First Known Use

1863, in the meaning defined above

Rhymes for sepsis

• antisepsis
• asepsis

Medical Definition

sepsis

noun

sep·​sis ˈsep-səs 

plural sepses ˈsep-ˌsēz 

: a potentially life-threatening, systemic response of the immune system that results from the spread of pathogenic agents (as bacteria or viruses) and their toxins to the bloodstream from a localized infection (as of the lungs), that involves both inflammatory and immunosuppressive activity, and that is marked especially by fever, chills, rapid heart rate and breathing, fatigue, confusion, increased blood coagulation, hypotension, impaired microcirculation, and organ dysfunction, and that may progress to septic shock

Note: The primary cause of sepsis is pneumonia with secondary causes commonly including infections of the abdominal cavity and urinary tract.

compare multiple organ dysfunction syndrome, septicemia