A changing definition
"Sepsis" comes from the Greek for putrefaction, and Hippocrates used it for the decay of wounds that could bring down the whole body. In 1847 Ignaz Semmelweis showed that simply having doctors wash their hands sharply reduced deaths from puerperal (childbed) fever, a form of sepsis, but he was largely ignored in his lifetime. Modern medicine first defined sepsis at a 1991 North American consensus conference as infection plus a systemic inflammatory response syndrome (SIRS). Criticised as too broad, that definition was replaced in 2016 by the Third International Consensus (Sepsis-3): life-threatening organ dysfunction caused by a dysregulated host response to infection. The key idea is that the body's own immune response runs out of control and damages its organs.
Causes and symptoms
Pneumonia, urinary tract infections, abdominal infections and skin or wound infections are common starting points, and not only bacteria but viruses (COVID-19, influenza) and fungi can trigger it. Older adults, infants, people with diabetes or cancer and those on immunosuppressants are at greatest risk. Suspect sepsis with fever or a low temperature, rapid breathing, a racing heart, reduced urine, mottled skin, or confusion and slurred speech. In emergency departments, two or more of the three signs below flag a patient for urgent assessment. If blood pressure stays low despite fluids — septic shock — mortality can exceed 40%.
| Warning sign (qSOFA) | Threshold |
|---|---|
| Breathing rate | 22 or more per minute |
| Mental state | New confusion or altered mentation |
| Systolic blood pressure | 100 mmHg or lower |
Treatment and prevention
Sepsis is a race against time. A 2006 study by Anand Kumar and colleagues found that in septic shock each hour's delay in effective antibiotics cut survival by roughly 8%. The Surviving Sepsis Campaign guidelines recommend taking blood cultures as soon as sepsis is suspected, then giving broad-spectrum antibiotics within an hour, adequate fluids and, if needed, vasopressors. Antibiotics from penicillin onward transformed survival, but antibiotic-resistant infections make treatment harder. An estimated 49 million people developed sepsis in 2017 and 11 million died — about one in five deaths worldwide — and the World Health Assembly made sepsis a global health priority in 2017. Hand-washing, pneumococcal and flu vaccination, good wound care and prompt treatment of infections are the basics of prevention.
This article is general health information and is not a substitute for diagnosis or treatment. If symptoms persist, see a doctor.
FAQ
- Is sepsis contagious?
- Sepsis itself is not contagious, but the infection that caused it, such as pneumonia or flu, may spread from person to person.
- Is sepsis the same as blood poisoning (bacteraemia)?
- No. Bacteraemia means bacteria are present in the blood; sepsis means infection has caused organ dysfunction. Sepsis can occur without bacteraemia.
Sources reviewed: 2026-10-26
References
- Singer, M., et al. (2016). The Third International Consensus Definitions for Sepsis and Septic Shock (Sepsis-3). JAMA, 315(8), 801–810.
- Bone, R. C., et al. (1992). Definitions for sepsis and organ failure and guidelines for the use of innovative therapies in sepsis. Chest, 101(6), 1644–1655.
- Rivers, E., et al. (2001). Early goal-directed therapy in the treatment of severe sepsis and septic shock. New England Journal of Medicine, 345(19), 1368–1377.
- Kumar, A., et al. (2006). Duration of hypotension before initiation of effective antimicrobial therapy is the critical determinant of survival in human septic shock. Critical Care Medicine, 34(6), 1589–1596.
- Rudd, K. E., et al. (2020). Global, regional, and national sepsis incidence and mortality, 1990–2017: analysis for the Global Burden of Disease Study. The Lancet, 395(10219), 200–211.
- Evans, L., et al. (2021). Surviving Sepsis Campaign: International guidelines for management of sepsis and septic shock 2021. Intensive Care Medicine, 47, 1181–1247.
- Semmelweis, I. P. (1861). Die Ätiologie, der Begriff und die Prophylaxis des Kindbettfiebers. Pest, Wien und Leipzig: C. A. Hartleben.
- World Health Organization. (2020). Global Report on the Epidemiology and Burden of Sepsis. Geneva: WHO.