What’s the difference between sepsis and septicaemia?

March 2019

If you or someone you know is seriously ill, the last thing you want to worry about is medical terminology. But we often hear from people who have been given a diagnosis of ‘meningococcal septicaemia’ or ‘pneumococcal septicaemia’, only later to be told they had meningitis, or sepsis, or both. So what’s the difference?

These are all words we use to describe life-threatening infection. They can occur together, or separately. When bacteria invade the body, this can cause severe illnesses which may result in death.

  • Septicaemia is when bacteria enter the bloodstream, and cause blood poisoning which triggers sepsis.
  • Sepsis is an overwhelming and life-threatening response to infection that can lead to tissue damage, organ failure and death.
  • Meningitis is when infection reaches the lining around the brain and spinal cord (the meninges) which can cause dangerous swelling.

The name of the bacteria that causes the infection is sometimes used by doctors too. For example, meningococcal, pneumococcal and Group B Streptococcal bacteria are all important causes of meningitis, septicaemia and sepsis.

It isn’t just bacteria that can cause meningitis and sepsis, however – they can also be caused by viruses and fungi. You can find out more about the different causes here.

Still confused?

Don’t worry. The main thing to know is that the words are all related to a serious life-threatening response to infection. Doctors need to worry about the finer details, but you just need to know how to spot the symptoms, or how to get support if you are affected. Here’s how:

The truth is they are all very serious, and the main thing to worry about is acting quickly if someone is getting very ill very fast.

Many causes of life-threatening meningitis, septicaemia and sepsis can be prevented by vaccines, so it’s also important for children and teenagers to get the vaccines they are eligible for. You can find out more about UK and Ireland immunisation schedules here, or give our helpline team a call on 080 8800 3344 if you have any questions.

The NHS in the UK is slowly phasing out the use of the word septicaemia in some environments to only use ‘sepsis’. However, research tells that parents particularly still respond to and want to be informed about septicaemia. While that is still happening, we'll continue to use all three words on our website and materials.

Since the charity was founded in 1989, we have awarded 161 research grants. The total value of our investment in vital scientific research is over £19.1 million (€24.7 million).
You don’t need to face meningitis and sepsis alone
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About the author

Rob Dawson
Director of Advocacy, Communications and Support

I joined in 2016 after seeing the great work the charity does to help people affected by meningitis and septicaemia. I have worked in communications for a range of sectors and bring experience from industry, charities and government.

Tel: 0333 405 6262