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

The rambunctious 4-year-old – who loved mud and getting dressed up and having dance parties with her brother and sisters – died January 6, after the flu and a co-infection with an adenovirus turned into pneumonia and sepsis. —Brenda Goodman, CNN Money, 16 Jan. 2026

Rather, their lawsuit suggested that the incident caused bacteria to get into Cardenas’ lungs, resulting in pneumonia and later sepsis that overwhelmed his body’s organs. —Jakob Rodgers, Mercury News, 14 Jan. 2026

Bacterial meningitis can progress quickly, causing the brain to swell and limbs to develop gangrene and sepsis, and can kill within 24 hours. —Kaitlin Sullivan, NBC news, 11 Jan. 2026

Meningitis can spread easily and cause brain swelling, sepsis, loss of hearing or limbs, and death. —Isabella Cueto, STAT, 6 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