Septic shock is a life-threatening condition that happens when your blood pressure drops to a dangerously low level after an infection.

Any type of bacteria can cause the infection. Fungi such as candida and viruses can also be a cause, although this is rare.

At first the infection can lead to a reaction called sepsis. This begins with weakness, chills, and a rapid heart and breathing rate.

Left untreated, toxins produced by bacteria can damage the small blood vessels, causing them to leak fluid into the surrounding tissues.

This can affect your heart's ability to pump blood to your organs, which lowers your blood pressure and means blood doesn't reach vital organs, such as the brain and liver.

People with a weakened immune system have an increased risk of developing septic shock.

This includes:

Symptoms of septic shock

Symptoms of septic shock include:

Septic shock is a medical emergency. Dial 999 to ask for an ambulance if you think that you or someone in your care has septic shock.

Treating septic shock

You'll usually be admitted to an intensive care unit (ICU) so your body's functions and organs can be supported while the infection is treated. In some cases treatment may start in the emergency department.

Treatment may include:

  • oxygen therapy
  • fluids given directly through a vein (intravenously)
  • medication to increase your blood flow
  • antibiotics 
  • surgery (in some cases)

Read more about treating septic shock.

Complications of septic shock

The chances of surviving septic shock will depend on:

  • the cause of infection
  • the number of organs that have failed
  • how soon treatment is started

Complications of septic shock can include:

  • inability of the lungs to take in enough oxygen (respiratory failure)
  • the heart not being able to pump enough blood around the body (heart failure)
  • kidney failure or injury 
  • abnormal blood clotting

These are serious health conditions that will need to be treated urgently. Septic shock can be fatal because of complications like these.


Sepsis occurs when an infection spreads through the blood, causing symptoms throughout the whole body. It's sometimes referred to as septicaemia or blood poisoning, but these terms aren't the same as sepsis.

Sepsis is where the body's defence mechanisms respond to an infection in some part of the body, resulting in symptoms such as a fever, raised pulse rate, raised breathing and confusion.

Septicaemia – another name for blood poisoning – is a bacterial infection of the blood that leads to the spread of infection and organ damage.

Page last reviewed: 18/02/2015

Next review due: 18/02/2017