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

Across the state, cases of sepsis in second-trimester pregnancy losses shot up more than 50% after the ban took effect, according to a data analysis by ProPublica. —Cassandra Jaramillo, CNN Money, 9 Feb. 2026

When his condition escalated to severe pneumonia and sepsis, his heart stopped and the team performed CPR, according to a press release on the case. —Melissa Rudy, FOXNews.com, 5 Feb. 2026

That is why the studies saw fewer cases of sepsis and necrotizing enterocolitis in babies who received breast milk or donor breast milk. —Nicole Villalpando, Austin American Statesman, 30 Jan. 2026

Actress Tanya Roberts, best known for her roles in the television series Charlie’s Angels and That ’70s Show, died in 2021 after a urinary tract infection developed into sepsis. —Miriam Fauzia, Dallas Morning News, 29 Jan. 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