About sepsis

Immediate action required: Phone 999 immediately or go to A&E if:

You or someone else has symptoms like:

  • loss of consciousness
  • severe breathlessness
  • a high temperature (fever) or low body temperature
  • a change in mental state – like confusion or disorientation
  • slurred speech
  • cold, clammy and pale or mottled skin
  • a fast heartbeat
  • fast breathing
  • chills and shivering
  • severe muscle pain
  • feeling dizzy or faint
  • nausea and vomiting
  • diarrhoea

What is sepsis?

Sepsis is a rare but serious complication of an infection.

Without quick treatment, sepsis can lead to multiple organ failure and death.

What causes a sepsis infection?

The immune system usually keeps an infection limited to one place. This is called a localised infection. To do this, the body produces white blood cells.

White blood cells travel to an infection site to destroy the germs causing the infection. This triggers tissue swelling, known as inflammation. This helps to fight the infection and prevent it from spreading.

However, an infection can spread to other parts of the body if the immune system is weak or an infection is severe.

Widespread inflammation can damage tissue and interfere with blood flow. When blood flow is interrupted, blood pressure can drop dangerously low. This stops oxygen from reaching the organs and tissues.

Sources of infection

Sepsis can be triggered by an infection in any part of the body. The most common sites of infection that lead to sepsis are the:

  • lungs
  • urinary tract
  • tummy (abdomen)
  • pelvis

However, sometimes the specific infection and source of sepsis can't be identified.

Infections linked to sepsis
  • appendicitis – infection in the appendix
  • cellulitis – a skin infection that can be caused by an intravenous catheter that's been inserted through the skin to give fluids or medication
  • cholangitis – an infection of the bile duct
  • cholecystitis – an infection of the gallbladder
  • encephalitis - an infection of the brain and nervous system
  • endocarditis – a heart infection
  • flu – only in some cases
  • meningitis – an infection of the brain and nervous system
  • peritonitis – an infection of the thin layer of tissue that lines the abdomen
  • pneumonia - a lung infection
  • post-surgery infections
  • osteomyelitis – a bone infection
  • urinary tract infection – an infection of the bladder, urethra or kidneys

Tests to diagnose sepsis

Sepsis is often diagnosed by testing your:

  • temperature
  • heart rate
  • breathing rate
  • blood

Other tests can help determine the type of infection, where it's located and which parts of the body have been affected. These include:

  • urine or stool samples
  • a wound culture – where a small sample of tissue, skin or fluid is taken from the affected area for testing
  • respiratory secretion testing – taking a sample of saliva, phlegm or mucus
  • blood pressure tests
  • imaging studies – like an X-ray, ultrasound scan or computerised tomography (CT) scan

Who’s at risk of sepsis?

Anyone can develop sepsis after an injury or minor infection. However, some people are more vulnerable, including people who:

  • are very young
  • are very old
  • are pregnant
  • have had a urinary catheter fitted
  • have a long term health condition like diabetes
  • have recently had surgery
  • are genetically prone to infections
  • are already in hospital with a serious illness
  • have to stay in hospital for a long time
  • have wounds or injuries as a result of an accident
  • have a medical condition that weakens the immune system – like HIV or leukaemia
  • are receiving medical treatment that weakens the immune system – like chemotherapy or long-term steroids
  • are on mechanical ventilation – where a machine is used to help you breathe

Recovering from sepsis

Some people make a full recovery from sepsis fairly quickly. The amount of time it takes to fully recover from sepsis varies depending on:

  • the severity of the sepsis
  • the person's overall health
  • how much time was spent in hospital
  • whether treatment was needed in an intensive care unit (ICU)

Long term effects of sepsis

Some people with sepsis will experience long-term physical and psychological problems. This is known as post-sepsis syndrome.

Symptoms of post-sepsis syndrome include:

  • feeling lethargic or excessively tired
  • muscle weakness
  • swollen limbs
  • joint pain
  • chest pain
  • breathlessness

Symptoms of sepsis

Sepsis can cause a variety of symptoms.

Sepsis symptoms in children under 5


  • over 38C (babies under 3 months)
  • over 39C (babies aged 3 to 6 months)
  • below 36C – check 3 times in a 10-minute period
  • a high temperature in a child who can’t be encouraged to show interest in anything


  • difficulty breathing – this looks like hard work
  • grunting with every breath
  • struggling to speak more than a few words at once (for older children who normally talk)
  • breathing that obviously "pauses"

Eating and drinking

  • no interest in feeding (child under 1 month)
  • not drinking for more than 8 hours (when awake)
  • black, green or bloody vomit


  • a soft spot on a baby's head that bulges
  • “sunken” eyes
  • a baby that’s floppy
  • a child that can’t be encouraged to show interest in anything
  • weak, whining or continuous crying in a younger child
  • confusion in an older child
  • irritableness
  • unresponsive
  • stiffness in the neck, especially when trying to look up or down
  • not had a wee or wet nappy for 12 hours

Immediate action required: Go to A&E or call 999 if your child:

  • is very lethargic or difficult to wake
  • feels abnormally cold to touch
  • is breathing very fast
  • has a rash that does not fade when you press it
  • has a fit or convulsion

Trust your instincts and phone 111 if your child’s symptoms are getting worse or they are sicker than you'd expect (even if their temperature falls).

Sepsis symptoms in older children and adults

Early symptoms of sepsis may include:

  • a high temperature (fever) or low body temperature
  • chills and shivering
  • a fast heartbeat
  • fast breathing

Symptoms of severe sepsis or septic shock

In some cases, symptoms of more severe sepsis or septic shock (when your blood pressure drops to a dangerously low level) develop.

These can include:

  • feeling dizzy or faint
  • a change in mental state – like confusion or disorientation
  • diarrhoea
  • nausea and vomiting
  • slurred speech
  • severe muscle pain
  • severe breathlessness
  • less urine production than normal – for example, not urinating for a day
  • cold, clammy and pale or mottled skin
  • loss of consciousness

Urgent advice: Phone 999 or go to A&E if:

  • you've recently had an infection or injury and you have possible signs of sepsis
  • you think you or someone in your care has severe sepsis or septic shock

Don't be afraid to ask the healthcare professional 'is this sepsis?'.

Treating sepsis

Treatment for sepsis varies, depending on the:

  • area affected
  • cause of the infection
  • organs affected
  • extent of any damage

If you have the early signs of sepsis, you'll usually be referred to hospital. You'll then be given a diagnosis and treatment.

Emergency treatment

You'll need emergency treatment, or treatment in an intensive care unit (ICU), if:

  • the sepsis is severe
  • you develop septic shock – when your blood pressure drops to a dangerously low level

ICUs can support body functions like breathing that are affected by sepsis. This allows the medical staff to focus on treating the infection.

Sepsis is treatable if it's identified and treated quickly. In most cases it leads to full recovery with no lasting problems.


The main treatment for sepsis, severe sepsis or septic shock is antibiotics. These will be given directly into a vein (intravenously).

Ideally, antibiotic treatment should start within an hour of diagnosis.

Intravenous antibiotics are usually replaced by tablets after 2 to 4 days. You may have to take them for 7 to 10 days or longer, depending on the severity of your condition.

Types of antibiotics

If sepsis is suspected, broad-spectrum antibiotics are given first. This is because there won't be time to wait until a specific type of infection has been identified.

Broad-spectrum antibiotics work against a wide range of known infectious bacteria. They usually cure most common infections.

Once a specific bacterium has been identified, a more focused antibiotic can be used.

Viral infections

If the sepsis is caused by a virus, antibiotics won't work. However, it would be too dangerous to delay treatment to find out the specific cause. This means antibiotics are usually given anyway.

With a viral infection, you'll need to wait until your immune system starts to tackle it. However, antiviral medication may be given in some cases.

Intravenous fluids

If you have sepsis, your body needs more fluid to prevent dehydration and kidney failure.

If you have severe sepsis or septic shock, you'll usually be given fluids intravenously for the first 24 to 48 hours.

It's important that the doctors know how much urine your kidneys are making when you have sepsis. This helps them spot signs of kidney failure.

If you're admitted with severe sepsis or septic shock, you'll usually be given a catheter. This is inserted into your bladder to monitor your urine output.


Your body's oxygen demand goes up if you have sepsis.

If you're admitted to hospital with sepsis and the level of oxygen in your blood is low, you'll usually be given oxygen. This is given through a mask or tubes in your nostrils.

Treating the source of infection

If a source of the infection can be identified, like an abscess or infected wound, this will also need to be treated.

For example, any pus may need to be drained away. In more serious cases, surgery may be needed to remove the infected tissue and repair any damage.

Increasing blood pressure

Medications called vasopressors are used if you have low blood pressure caused by sepsis.

Vasopressors are normally given intravenously while you're in an ICU. Extra fluids may also be given intravenously to help increase blood pressure.

Other treatments

You may require additional treatments like:

  • corticosteroids
  • insulin medication
  • a blood transfusion
  • mechanical ventilation – where a machine is used to help you breathe
  • dialysis – where a machine filters your blood to copy the function of your kidneys

These treatments are mostly used in ICUs.

Last updated:
25 January 2023