Your browser is no longer supported

For the best possible experience using our website we recommend you upgrade to a newer version or another browser.

Your browser appears to have cookies disabled. For the best experience of this website, please enable cookies in your browser

We'll assume we have your consent to use cookies, for example so you won't need to log in each time you visit our site.
Learn more

Blood poisoning

  • Comment

It is estimated that there are 31,000 cases of severe sepsis in England and Wales every year, and the number of cases seems to be rising. Approximately 30% to 50% of people with severe sepsis will die because of the condition.
Brought to you by NHS Choices



Sepsis refers to an infection that has spread through the blood, causing symptoms throughout the whole body. This is known as a systematic response.

Sepsis is often referred to as either blood poisoning or septicaemia, though it could be argued that both terms are not entirely accurate. Sepsis is not just limited to the blood but can affect the whole body, including the organs. Septicaemia refers to a bacterial infection of the blood; whereas sepsis can also be caused by viral or fungal infections.

Usually, an infection is limited to one part of the body. This is referred to as a localised infection. However, if somebody is particularly vulnerable to infection, for example they have a weakened immune system, the infection can carry on spreading. The infection will spread first into the blood and then into other organs.

Unfortunately, rather that helping to get rid of sepsis, the immune system actually makes it worse. This is because the immune system releases a high number of infecting-fighting proteins known as cytokines. These proteins, rather than fighting the infection, actually cause damage to the organs of the body and affect blood circulation.

Severe sepsis and septic shock

If sepsis is allowed to progress, it can move into a more serious phase of the condition known as severe sepsis. Severe sepsis happens when one or more organs have been damaged by the infection, or there is a significant loss of blood supply to tissues and organs (hypoperfusion).

Septic shock is another type of sepsis where the infection causes a massive drop in blood pressure. This results in symptoms of shock, such as cold skin and increased heart beat.

Sepsis can interfere with many of the vital processes of the body, including blood pressure, breathing and organ function; all of which can result in death.

Treatment will normally require admission to an intensive care unit (ICU) where the functions of the organs and body can be supported while the infection is treated.


Symptoms of blood poisoning

The symptoms of sepsis may develop as a response to a localised infection or injury.

In some cases, symptoms may develop when you are already in hospital. For example, if you have recently had surgery or intravenous lines or catheters have been connected to your body.

The symptoms of sepsis usually develop quickly and include:

  • a fever,
  • fast heart beat, and
  • fast breathing.

Symptoms of severe sepsis or septic shock include:

  • low blood pressure which will result in you feeling dizzy when you stand up,
  • a change in mental behaviour such as confusion or disorientation,
  • diarrhoea,
  • reduced urine flow,
  • cold, clammy skin,
  • pale skin, and
  • loss of consciousness.

Severe sepsis and septic shock are medical emergencies. If you suspect that you or someone in your care are experiencing these conditions, phone 999 and ask for an ambulance.


Causes of blood poisoning

Sepsis begins either as a result of a localised (confined to a particular location) infection, such as lung infection (pneumonia), or as a result of a severe injury, such as a burn or gunshot wound.

Usually, your immune system will keep the infection localised in once place. Your body will produce white blood cells which travel to the site of the infection. This process is called inflammation. The function of the white blood cells is to destroy the infection and repair damaged tissue.

However, if your immune system is weakened, or the infection or injury is particularly severe, the infection can spread through the blood into other parts of the body. This causes the immune system to go into ‘overdrive’ which then spreads the process of inflammation throughout the entire body.

This can cause more problems than the actual infection, as widespread inflammation causes damage to tissue and interferes with the flow of blood. In turn, this leads to a drop in blood pressure and stops oxygen reaching your organs and tissue.

Sources of infection

Types of infection associated with sepsis are:

  • lung infection (pneumonia),
  • flu (influenza),
  • appendicitis,
  • infection of the lining of the digestive system (peritonitis),
  • an infection of the bladder, urethra or kidneys (urinary tract infection),
  • skin infections - often caused when an intravenous drip or catheter has been inserted into the body through the skin,
  • post-surgical (after surgery) infections, and
  • infections of the nervous system such as meningitis or encephalitis.

People at risk

People particularly vulnerable to sepsis include:

  • people who have a medical condition that affects their immune system such as HIV or leukaemia,
  • people who are receiving medical treatment that weakens their immune system, such as chemotherapy or long-term steroid injections, and
  • the very young or the very old.

Sepsis is also a risk for people who are already in hospital due to another serious illness. Despite the best efforts of doctors and nurses, secondary infections acquired in hospital are always a possibility. Also, hospital-acquired bacterial infections, such as MRSA, tend to be more serious as they have often developed a resistance to antibiotics.


Diagnosing blood poisoning

There are three important goals when diagnosing sepsis. These are:

  • determine the type of infection,
  • determine the source of infection, and
  • determine which and how badly other body functions have been affected.

To diagnose sepsis, several tests may be carried out, including:

  • blood tests,
  • urine tests,
  • stool sample tests,
  • blood pressure tests,
  • a wound culture test - where a small sample of tissue, skin or fluid is taken from the affected area for testing,
  • respiratory secretion testing - which involves testing a sample of your saliva, phlegm or mucus,
  • imaging studies such as an X-Ray or CT Scan,
  • kidney, liver and heart function tests, and
  • a spinal tap - where a sample of cerebrospinal fluid is extracted from your back for testing.


Treating blood poisoning

If your sepsis is detected early enough and has not affected organ or tissue function (uncomplicated sepsis), it may be possible to treat the condition at home. You will be prescribed a course of antibiotic tablets to be taken by mouth (oral antibiotics).

If the sepsis is severe or symptoms of shock are present, hospital treatment will be required, usually in an Intensive Care Unit (ICU’s).

ICU’s are able to help support any affected body function, such as breathing or blood circulation, while the medical staff focus on treating the infection.


Severe sepsis is treated with intravenous antibiotics. Often there will not be time to wait until a specific type of infection has been identified. Therefore, the initial treatment uses what is known as ‘broad-spectrum’ antibiotics. Broad spectrum antibiotics are designed to work against a wide range of known infectious bacteria. They can also treat some fungal infections.

Once a specific bacterium has been identified, a more ‘focused’ antibiotic can be used. This has the advantage of reducing the chances of bacteria becoming resistant to antibiotics.

If the sepsis is caused by a virus, antibiotics will not work. It is necessary to wait until the body develops a resistance to the effects of the virus. In some cases, anti-viral agents may be given. However, it is likely that antibiotic treatment will be started anyway. This is because it would be too dangerous to delay antibiotic treatment until an accurate diagnosis is made.

Intravenous antibiotics usually have to be administered for seven to 10 days.

Source control

Source control means to treat the source of the infection, such as an abscess or infected wound. This may require draining pus from infected tissue.

In more serious cases, surgery may be required to remove the infected tissue and repair any damage.


Vasopressors are medicines that are used to treat low blood pressure. The two types of vasopressors used in the treatment of sepsis are dopamine and norepinephrine.

Both of these are actually neurotransmitters which are naturally occurring chemicals found in the brain. They can help to increase blood pressure by stimulating the muscles involved in pumping blood around the body and widening the blood vessels.

Vasopressors are normally administered intravenously.

Extra fluids may also be administered intravenously as this will also help increase blood pressure.

Recombinant Human Activated Protein C (rhAPC)

Recombinant Human Activated Protein C (rhAPC) is a new type of medicine that is now being used to treat some cases of severe sepsis. The type of rhAPC used in the UK is known as drotrecogin alfa. It contains a genetically modified type of protein molecule called Protein C. Protein C is known to reduce levels of inflammation and help prevent blood clots; both important goals in the treatment of sepsis.

Drotrecogin alfa is known to cause internal bleeding in some people. So this treatment may not be suitable for you if you have had a previous history of stroke, internal injury or have recently had surgery.


Preventing blood poisoning

If you have a weakened immune system, or are particularly vulnerable to the effects of infection, you will need to take extra precautions.

These are outlined below.

  • Avoid smoking - this will weaken your immune system.
  • Do not use illegal drugs - these also weaken your immune system.
  • Make sure that your immunisations are up to date - your GP will be able to advise you. Vaccinations are available for some of the common infections associated with sepsis such as pneumonia and influenza.
  • Eat a healthy diet - this will boost your immune system.
  • Take regular exercise - this will boost your immune system.
  • Wash your hands regularly - particularly after going to the toilet, before and after preparing food, and after spending time in crowded places.

You should also be watchful for the initial signs of infection and report any symptoms promptly to your GP.

These include:

  • redness or swelling in the affected area,
  • pain or tenderness in the affected area,
  • discharge, pus or foul-smelling fluid, and
  • fever

Complications of arthritis 

Some treatments for arthritis have side effects that may cause additional problems. NSAIDs may damage the stomach and digestive system and are also associated with kidney problems in some people. Corticosteroids can cause reduction in bone density (osteoporosis) leading to increased risk of fractures and may also lead to the development of shingles, cataracts, and diabetes.

In the long term, arthritis can produce worsening pain, loss of mobility, and sometimes make walking difficult, or impossible. As a result, depression may accompany this condition.

General effects of rheumatoid arthritis may include:

  • loss of appetite and weight,
  • tiredness,
  • muscle pain,
  • lumps (nodules) under the skin,
  • inflammation of tendons,
  • sight problems,
  • anaemia (blood disorder), and
  • vasculitis (inflammation of the blood vessels)

NHS Choices links

External links

This article was originally published by NHS Choices

  • Comment

Have your say

You must sign in to make a comment

Please remember that the submission of any material is governed by our Terms and Conditions and by submitting material you confirm your agreement to these Terms and Conditions. Links may be included in your comments but HTML is not permitted.

Related Jobs