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Southern Cross Medical Library

The purpose of the Southern Cross Medical Library is to provide information of a general nature to help you better understand certain medical conditions. Always seek specific medical advice for treatment appropriate to you. This information is not intended to relate specifically to insurance or healthcare services provided by Southern Cross. For more articles go to the Medical Library index page.

Sepsis – Causes, Symptoms, Treatment


Sepsis is a life-threatening condition caused by the body’s overreaction to an infection.

Symptoms include fever, breathing difficulties, increased heart rate, low blood pressure, and mental confusion. Prompt treatment with antibiotics and intravenous fluids will aim to limit organ damage and prevent death. 

It has been estimated that nearly 15,000 people in Australia and New Zealand are admitted to a hospital intensive care unit each year with sepsis, and a 2018 study in the Waikato region indicates some 20% of people die following admission.

Sepsis is often a result of blood stream infection (also known as septicaemia or blood poisoning).  Blood stream infection is when a bacterial infection elsewhere in the body (such as pneumonia in the lungs or cellulitis in the skin) enters the bloodstream, which can then trigger sepsis. 


The body normally releases chemicals into the bloodstream to fight an infection.  Sepsis occurs when the body’s immune system overreacts, and the chemicals intended to fight infection cause changes that damage the body’s tissues and vital organs.

In severe cases of sepsis, one or more organs fail. In the most serious cases, there is a massive drop in blood pressure and multiple organs fail quickly. This is known as septic shock, which has a high risk of death.

Sepsis can be triggered by an infection in any part of the body. Common sites of infection leading to sepsis are:

Risk factors

Although anyone can develop sepsis, the following factors increase the risk of sepsis:

  • Immunodeficiency disorders 
  • Younger age (infants and children)
  • Older age (65 years or older)
  • Frailty
  • Pregnancy
  • Chronic illnesses, e.g. diabetes, cancer, kidney disease, liver cirrhosis
  • Recent surgery or serious illness
  • A long stay in hospital, often in the intensive care unit (ICU)
  • Having an invasive device in your body, such as a breathing tube or catheter
  • Having recently received antibiotics or corticosteroids
  • Severe burns or other wounds or injuries.

Signs and symptoms

Most often, sepsis develops in people who are hospitalised or have recently been hospitalised.  You should seek urgent medical attention if you think you have symptoms of sepsis:

  • Fever (over 38 degrees celsius or under 35 degrees)
  • Chills and shivering
  • Rapid or laboured breathing (more than 22 breaths a minute)
  • Feeling unwell
  • Rapid heart rate (over 100 beats per minute)
  • Rash
  • Confusion and disorientation.


Initial steps in the diagnosis of sepsis involves measuring a person’s temperature, heart rate, breathing rate, and blood pressure.  Doctors often order several tests to diagnose the underlying infection, depending on your symptoms.  These may include blood tests, urine or stool tests, respiratory or wound secretion tests, and imaging studies (X-ray, CT, ultrasound, MRI).


Early and aggressive treatment of sepsis increases the chance of survival. Severe sepsis and septic shock require admission to hospital and some people may require admission to an intensive care unit. Because of problems with vital organs, people with severe sepsis are likely to be very ill and the condition can be fatal. 

Some people, especially those with pre-existing chronic diseases, may have permanent organ damage following recovery. Severe sepsis also disrupts a person’s immune system, making them more at risk for future infections. 

Treatment for sepsis depends on the site and the cause of the initial infection, the organs affected, and the extent of organ and tissue damage. The main aims of treatment are to resolve the infection and sustain the vital organs. This may involve giving: 

  • Intravenous (i.e. via a vein) antibiotics to stop the infection
  • Oxygen and intravenous fluids to maintain blood flow and the delivery of oxygen to tissues and body organs
  • Drugs that help to increase blood pressure. 

Other medications may be given to moderate the body’s immune system response, reduce pain and inflammation, and maintain blood sugar levels.

Supportive care, such as machines to help with breathing and kidney dialysis if the kidneys have been affected, may be necessary. Surgery is sometimes needed to remove infected tissues or gangrene.

Further information and support

Freephone (24 hours): 0800 611 116

Sepsis Trust NZ
Phone: +64 7 839 8899


Burrell, A., Huckson, S., Pilcher, D.V. (2018). ICU Admissions for Sepsis or Pneumonia in Australia and New Zealand in 2017. N Engl J Med. 2018;378(22):2138–2139.
Finfer, S., et al. (2004). Adult-population incidence of severe sepsis in Australian and New Zealand intensive care units. Intensive Care Med. 2004;30(4):589–96.
Mayo Clinic (2018). Sepsis (Web Page). Rochester, NY: Mayo Foundation for Medical Education and Research. [Accessed: 19/07/19]
National Institute of General Medical Sciences (2019). Sepsis (Web Page). Bethesda, MD: National Institutes of Health. [Accessed: 19/07/19]
NHS (2019). Sepsis (Web Page). Redditch: National Health Service (NHS) 
England. [Accessed: 19/07/19]
Stuff (2018). Doctor estimates thousands are dying of sepsis every year. [Accessed: 16/08/19]
BPAC New Zealand Guidelines (2018). Sepsis: recognition, diagnosis and early management. [Accessed: 16/08/19]

Update: August 2019

Go to our Medical Library Index Page to find information on other medical conditions.