The Differences Between Sepsis and Septicemia

The terms are similar, but they're not interchangeable

A test tube rack of biohazardous samples in the lab.
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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, sepsin, which literally means "poison in putrid blood."

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 Is Widespread Inflammation in Your Body

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. It 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 some 258,000 Americans each year, and survivors can have life-long effects from the disease. There are more than 1 million cases of sepsis in the U.S. annually.

Symptoms of Sepsis

If you're experiencing symptoms of sepsis, which include fever, chills, mental confusion, rapid heartbeat, shaking, and warm skin, you should seek immediate medical help.

In some people, the first signs of sepsis are confusion and rapid breathing.

Elderly people, babies, young children, people with weakened immune systems, and people with a long-term chronic illness 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.

There are many different infections that can cause sepsis. Some possible causes include meningitis, urinary tract infections, skin infections, and abdominal infections. Infections also can start in the hospital from intravenous lines, surgical sites, and from bedsores. In fact, sepsis is common in people admitted to the hospital for other reasons.

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 Is the Infection Itself

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.

Doctors and other medical personnel no longer use the term septicemia much.

Instead, to eliminate the inevitable confusion surrounding such like-sounding terms as sepsis and septicemia, clinicians 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 doctors and hospitals do still use the older term "septicemia," in some cases interchangeably with sepsis. If you're confused about what exactly your doctor means, you should ask her to explain.

View Article Sources
  • Bacteremia. Merck Manual. https://www.merckmanuals.com/home/infections/bacteremia-sepsis-and-septic-shock/bacteremia.
  • Sepsis. MedlinePlus. https://www.cdc.gov/sepsis/basic/index.html.
  • Sepsis: Basic Information. Centers for Disease Control and Prevention. https://www.cdc.gov/sepsis/basic/index.html
  • Septicemia. MedlinePlus. https://medlineplus.gov/ency/article/001355.htm.