Sepsis, blood poisoning or septicaemia
Sepsis is a life-threatening illness caused when the body is overcome by infection. It is often called septicaemia or blood poisoning when the body is fighting a severe infection that has spread via the bloodstream.
This condition can develop either as a result of the body's own defence system or from toxic substances made by the infecting agent (such as a bacteria, virus or fungus).
There are three stages of sepsis:
- Uncomplicated sepsis is very common and usually does not need hospital treatment.
- When the infection starts to interfere with the organs of the body it is called severe sepsis.
- In severe sepsis, if blood pressure drops to dangerous levels, organs are prevented from getting enough oxygenated blood, and this is called ‘septic shock’.
People at risk of sepsis
- People whose immune systems (the body's defence against microbes) are not functioning well because of an illness (such as cancer or AIDS) or because of medical treatment (such as chemotherapy for cancer or steroids for a number of medical conditions) that weakens the immune system are more prone to develop sepsis. It is important to remember that even healthy people can suffer from sepsis.
- Because their immune systems are not completely developed, very young babies may get sepsis if they become infected and are not treated in a timely manner. Often, if they develop signs of an infection such as fever, infants have to receive antibiotics and be admitted to hospital. Sepsis in the very young is often more difficult to diagnose because the typical signs of sepsis (fever, change in behaviour) may not be present or may be more difficult to ascertain.
- The elderly population, especially those with other medical illnesses such as diabetes, may be at increased risk as well.
The number of people developing sepsis in the UK appears to be increasing with more than 30,000 cases of severe sepsis occurring each year.
- There has been a large increase in sepsis because doctors have started treating cancer patients and organ transplant patients, among others, with strong medications that weaken the immune system.
- Because of our ageing population, the number of elderly people with weak immune systems has also grown.
- Finally, because of the increased and often inappropriate use of antibiotics to treat illnesses caused by viruses and not bacteria, many strains of bacteria have become resistant to antibiotics, making the treatment of sepsis more difficult in some cases.
Many different microbes can cause sepsis. Although bacteria are most commonly the cause, viruses and fungi can also cause sepsis. Infections in the lungs ( pneumonia), bladder and kidneys ( urinary tract infections), skin ( cellulitis), abdomen (such as appendicitis), and other organs (such as meningitis) can spread and lead to sepsis. Infections that develop after surgery can also lead to sepsis.