Sepsis is a life threatening emergency. It happens when your body responds to an infection. The immune system of the body helps fight the infection. At the same time the immune system is fighting the infection it can also cause damage to the body.

Sepsis needs to be treated at the start of the infection. This is because it can become severe quickly. Organ failure and death are more likely if sepsis isn't recognised early and treated.

Sepsis can happen to anyone but is more likely when people are old or frail. It is also more likely in those who have recently had surgery and those with a weak immune system. Those with a weak immune system include people on cancer treatment or a chronic illness. Sepsis can affect one or all of the body systems.

Each year around 18,000 people are treated in an ICU in Australia and New Zealand for severe sepsis. The number of people treated for sepsis is increasing because:

  • the population is ageing
  • more people have chronic illnesses
  • more people are getting being treated with immunosuppressive drugs, chemotherapy, and organ transplants
  • bacteria are becoming more resistant to antibiotics

Causes of sepsis

Sepsis can arise from an infection in the lungs, urinary tract, skin, abdomen or other part of the body. Bacteria, fungi and viruses can all cause sepsis. Bacteria are the most common cause.

The most common causes of sepsis are:

  • respiratory infections
  • abdominal infections (for example, after kidney or gall stones)
  • urinary infections

Sepsis may occur in patients in the community and those already in hospital. Sepsis can also occur due to an infection after surgery.


The symptoms of sepsis depend on how severe the illness is. They can include:

  • fevers or shivering
  • chills
  • fast breathing/ difficulty breathing
  • rapid heartbeat
  • low blood pressure
  • confusion
  • poor appetite
  • skin rash or discoloured skin
  • urinating less

Diagnosing sepsis

You will have to have a number of different tests to diagnose sepsis. These will include blood tests, urine tests, lab tests on body fluids, X-rays or scans.

These blood and fluids will be sent for analysis, looking for bacteria or other microbes. These can take several days to give a result. Depending on where your infection is coming from, you may need other tests that look at different parts of your body.


Sepsis, is usually treatable by giving antibiotics through the vein as soon as possible. Sometimes surgery will be required to clear a site of infection. This might be needed for an abscess or a bowel perforation. Despite years of research, scientists have not yet succeeded in developing a medicine that specifically targets the aggressive immune response in sepsis.

If you have severe sepsis, you may need other treatments to support your breathing, kidneys and blood pressure. This requires admission to ICU.

You may need to have a breathing tube attached to a ventilator. If your kidneys are affected, you may also need to go onto a dialysis machine.


Sepsis is a severe life-threatening condition that can take people a long time to recover from. Your recovery will depend on the source of your infection. It will also depend on what treatments you need as you recover.

Some people have long term effects after sepsis. This is called “Post-Sepsis Syndrome”. Some of the symptoms of “post-sepsis syndrome” overlap with “Post-Intensive Care Syndrome (PICS)“.

Some of the symptoms of Post-Sepsis Syndrome include:

  • sleep disturbance including insomnia
  • nightmares, hallucinations, flashbacks and panic attacks
  • muscle and joint pains which can be severe and disabling
  • extreme tiredness and fatigue
  • difficulties concentrating
  • impaired mental (cognitive) functioning
  • loss of confidence and self-belief

Preventing sepsis from happening again

The Australian Sepsis Network says:

  • 40% of sepsis survivors will return to hospital within 30 days
  • 75% of sepsis survivors will return to hospital within 1 year
  • sepsis reoccurs in about 25% of patients

It is important to seek medical attention when you get any infection. Vaccines can also prevent serious infections. Speak to your GP to make sure you are up to date with your vaccines.

Related topics


This topic has been reviewed by an intensive care medicine specialist in July 2022.

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