Difference Between Sepsis and Septicemia

Sepsis and septicemia are medical terms that refer to infections and your body's response to those infections. Both words originally stem from a Greek word, sēpsis, which literally means "to make rotten" or "to putrefy."

Heart monitor with a man on life support in the background
Caia Images / Sam Edwards

Sepsis and septicemia sometimes are used interchangeably, but they're not truly interchangeable—although the terms are closely related, their definitions are different. Learn the correct use of each word when you're talking about infections.

Sepsis and Inflammation

Sepsis is defined as an extreme inflammatory response to infection. 

When your body is threatened with a severe infection your immune system responds by releasing chemical messengers to sound the alarm. These chemical messengers produce inflammation throughout your body.

The infection can be due to bacteria in the bloodstream, but sepsis can also be produced by an infection that is present only in one part of the body, such as the lungs in pneumonia.

The inflammation in sepsis can produce blood clots and leaking blood vessels. Without proper treatment, this can damage your organs and potentially kill you.

Sepsis can progress to septic shock with your blood pressure dropping and your bodily systems starting to shut down. Your lungs, liver, and kidneys can fail.

Therefore, sepsis is a medical emergency. In fact, sepsis kills almost 270,000 Americans each year, and survivors can have life-long effects from the disease. The U.S. has more than 1.7 million annual cases.

Causes and Symptoms

If you're experiencing symptoms of sepsis, you should seek immediate medical help. Symptoms include:

  • Fever
  • Chills
  • Mental confusion
  • Rapid heartbeat
  • Shaking
  • Warm skin

In some people, the first signs of sepsis are:

  • Confusion
  • Rapid breathing

Elderly people, babies, young children, people with weakened immune systems, and people with long-term chronic illnesses are most at risk from sepsis.

Treatment can involve antibiotics plus life support measures such as dialysis and a ventilator until the patient is stabilized.

Many different infections can cause sepsis. Some possible causes are:

Sepsis can also be acquired in a hospital from contaminated intravenous lines and surgical incisions.

According to research from the Centers for Disease Control and Prevention (CDC), the United States had 173,690 cases of hospital-acquired sepsis in 2014, representing roughly 6% of all hospital admissions.

Some of these infections result from so-called "superbugs," which are types of bacteria that are resistant to many different antibiotics. These infections and the resulting sepsis are very difficult to treat.

Septicemia and Infection

Septicemia is defined as having bacteria in the bloodstream that cause sepsis. Some people call septicemia "blood poisoning," and this term is pretty accurate since the overwhelming bacterial infection can indeed poison your blood.

Healthcare providers and other medical personnel no longer use the term septicemia much. To eliminate confusion surrounding like-sounding terms, they often use "sepsis" to refer to the inflammatory response and "bacteremia" to refer to the bacteria present in the bloodstream.

Other types of infections, such as fungal infections, have different names.

However, some healthcare providers and hospitals do still use the older term "septicemia," in some cases interchangeably with sepsis. If you're confused about what exactly your healthcare provider means, ask them to explain.

Septicemia is a bacterial infection that spreads into the bloodstream. Sepsis is the body's response to that infection, during which the immune system will trigger extreme, and potentially dangerous, whole-body inflammation.

5 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Hotchkiss RS, Moldawer LL, Opal SM, Reinhart K, Turnbull IR, Vincent JL. Sepsis and septic shockNat Rev Dis Primers. 2016;2:16045. doi:10.1038/nrdp.2016.45

  2. Centers for Disease Control and Prevention. Sepsis.

  3. National Institutes of Health. Sepsis.

  4. Owusu-Ansah S. Sepsis in infants & children. American Academy of Pediatrics.

  5. Rhee C, Dantes R, Epstein L, et al. Incidence and trends of sepsis in US hospitals using clinical vs claims data, 2009-2014JAMA. 2017;318(13):1241-1249. doi:10.1001/jama.2017.13836

By Trisha Torrey
 Trisha Torrey is a patient empowerment and advocacy consultant. She has written several books about patient advocacy and how to best navigate the healthcare system.