Everything You Need to Know About Sepsis: Causes, Symptoms, and Treatments
According to The UK Sepsis Trust, around 245,000 people are affected by sepsis each year – which means its’s more common than people may think.
And while it can be a serious condition, understanding exactly what sepsis is and recognising the early warning signs can make a real difference.
In this article, we’ll explain everything you need to know about sepsis, including what causes it, what symptoms to look out for, and how it’s treated.
What is sepsis?
Sometimes referred to as blood poisoning, sepsis happens when your body has an extreme reaction to an infection. Instead of just fighting the infection, your immune system goes into overdrive and starts damaging your own tissues and organs.
It can happen after something as simple as a cut or a minor infection, but sepsis can become life-threatening very quickly. That’s why it’s important to be aware of the early warning signs of sepsis, so you can catch it quickly and speak to your GP.
What are the three stages of sepsis?
Sepsis typically occurs over three progressive stages:
Sepsis: This is the earliest stage, where your body first begins to react strongly to an infection. You might feel hot or cold, have a fast heart rate, or breathe more quickly than usual. If you’re experiencing these symptoms, then it’s best to see your primary care clinician as soon as you can, as they’ll be able to help you before the sepsis goes onto later stages.
Severe sepsis: At this point, the infection is starting to affect one or more of your organs. You might feel confused, breathless, or find that you’re not urinating as often. At this stage, it’s best to go to A&E for advice and care.
Septic shock: This is the most serious stage. Your blood pressure drops very low and your organs may begin to fail. Septic shock is a medical emergency, so you need to call 999 or get to A&E and get immediate treatment.
What causes sepsis?
Sepsis is typically caused by an infection. This could be bacterial, viral, fungal, or even parasitic and often starts in the following areas of your body:
The lungs (such as pneumonia).
The urinary tract (such as cystitis).
The stomach or abdomen.
The skin (from cuts, bites, or wounds).
If that infection spreads or isn’t treated quickly enough, it can lead to sepsis. Certain people are also more at risk of getting sepsis than others, including babies and young children, older adults, people with weakened immune systems, and anyone recovering from surgery. Those living with long-term conditions, such as diabetes or kidney disease, are also at a higher risk.
How long does sepsis take to develop?
Sepsis can develop very fast - sometimes within just a few hours. That’s why it’s so important to understand the early warning signs of sepsis (both in yourself and others) and seek help if something doesn’t feel right.
Even if you’re unsure, it’s always best to book an appointment with a medical professional to put any lingering worries to rest.
Is sepsis contagious?
Sepsis itself isn’t contagious, so you can’t catch it directly from someone else. However, the infections that can cause sepsis (such as the flu or Covid-19) are contagious, so you still need to be vigilant when interacting with people who have an infection.
As such, it’s important to practice good hygiene, stay up to date with your vaccinations, and take care of your general wellbeing to help avoid sepsis or the infections that cause it.
What are the symptoms of sepsis?
With adults and older children, the early warning signs of sepsis can look and feel a lot like flu at first. This can make it quite tricky to spot at first, but there are some other symptoms to keep an eye out for:
- High temperature (fever) or low body temperature.
- Chills or shivering.
- Fast heartbeat.
- Rapid breathing.
- Feeling confused, dizzy or disoriented.
- Extreme pain or discomfort.
- Clammy or sweaty skin.
To help remember those warning signs, either for yourself or a loved one, the World Sepsis Day committee has developed the SEPSIS mnemonic:
Slurred speech or confusion.
Extreme shivering or muscle pain.
Passing no urine in 24 hours.
Severe breathlessness.
It feels like you’re going to die.
Skin that's mottled or discoloured.
If you or someone you’re with shows any of these symptoms, call 999 straight away. You can also contact 111 or your GP if you’re unsure whether you’re showing these early warning signs of sepsis.
Signs of sepsis in children, toddlers, and babies
As children’s immune systems are still developing and getting stronger, they’re more vulnerable to infections – which can then lead to sepsis. The signs of sepsis in children can also develop quite quickly, so it’s important to call 999 or go to A&E if you notice any of the following:
- Very fast breathing.
- Seizures or convulsions.
- Skin looks pale, mottled, or bluish.
- Rashes that doesn’t fade when pressed.
- Very sleepy or hard to wake up.
- Feels unusually cold.
There are also specific symptoms of sepsis in babies to watch out for as well:
- A soft spot on the head that looks swollen or bulging.
- Floppy limbs or low energy.
- Not feeding properly.
- Repeated vomiting (especially if it’s green or has blood in it).
Much like with adults, the difficulty is that some of these symptoms can be confused for the flu or just general sickness. Speak to your doctor or call 111 if you’re not certain about the symptoms, following their guidance to go to A&E or call 999, if necessary.
For more information, head over to the NHS’ sepsis page.
How do you treat sepsis?
If it’s caught early, treating sepsis in hospital is straightforward. You’ll likely be prescribed antibiotics to target the infection, once you’ve had blood tests taken and returned.
However, if it progresses to either severe sepsis or septic shock, you may need other types of treatment, such as:
Intravenous (IV) fluids: This helps to stabilise your blood pressure and volume, which can be severely impacted by sepsis, delivering oxygen and vital nutrients to your organs.
Oxygen therapy: Sepsis can reduce your blood’s oxygen levels, in turn, reducing the amount of oxygen your organs and tissue are receiving. This may be delivered via a ventilator.
Surgery: In extreme cases, you may need surgery to physically remove the areas of infection.
The sooner sepsis is identified, the more straightforward the treatment process. That’s why, again, it’s important to be familiar with those early warning signs of sepsis.
Can sepsis be cured?
Yes, many people make a full recovery from sepsis, especially when it’s caught and treated early. However, the recovery process can sometimes take a bit of time, potentially requiring you to stay in hospital for a few weeks.
Some people may also experience long-term effects of sepsis, known as post-sepsis syndrome. This can include fatigue, trouble concentrating, memory problems, lack of appetite, mood changes, and difficulty sleeping.
In these cases, people should recover from post-sepsis syndrome on their own – but the process might be slow and frustrating. It’s important to not rush your recovery and find ways to tweak your daily routine in the meantime.
How to avoid sepsis
According to the NHS, not all cases of sepsis can be prevented. However, there are steps you can take to lower the risk of infection that leads to sepsis:
Stay up to date on vaccinations: Particularly important for babies, children, older people, and pregnant women, you should keep up to date on jabs for the flu, pneumonia, and Covid-19.
Practice good hygiene: Wash your hands regularly throughout the day – as well as every time you go to the toilet. You should also ensure children understand the importance of doing so, too.
Look after your general wellbeing: Boost your immune system’s defences by eating a healthy, balanced diet, regular movement and practicing good sleep hygiene.
Clean and care for any wounds: Whether it’s a simple pet scratch or a cut from the kitchen, gently clean and dress any wounds to prevent infection.
Don’t ignore symptoms of sepsis: Even if you’re not 100% it’s sepsis, always speak to your GP or call 111 if you experience any of the symptoms.
How can Benenden Health help with sepsis?
If you’re ever unsure about the early warning signs of sepsis or just need some expert reassurance, Benenden Health members can access 24/7 GP Helpline from day one of the membership. It’s a quick and easy way to speak to a doctor and get advice, day or night.
Our affordable private healthcare membership gives you access to services like this straight away. And once you’ve been a member for six months (or 24 months in Northern Ireland), you can request diagnostic consultations and tests too.
Medically reviewed by Dr Cheryl Lythgoe in May 2025.
