Sepsis and septic shock

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Sepsis is an abnormal response to an infection. It occurs when the immune system can't fight an infection and so it quickly spreads through the body. It can also occur when the immune system overreacts to an infection. When the immune system is working properly, it only attacks an infection at its source. After it fights the infection, the immune response normally shuts off so nearby tissue isn't damaged. In sepsis, the immune response doesn't shut off and the inflammatory reaction spreads throughout the body.

People with cancers of the blood, such as leukemia, are more likely to get sepsis than people who have solid tumours. Certain cancer treatments, such as chemotherapy, can also increase your risk of getting sepsis.

Sepsis is a serious health problem. When severe, sepsis can lead to septic shock if your blood pressure drops dangerously low. This can lead to the failure of important organs like the lungs, kidneys or liver. For this reason, septic shock can be a life-threatening condition.


Sepsis is an abnormal response to an infection. The infection is usually caused by bacteria, but sometimes it can be caused by fungi and viruses. Bacteria can get into the lungs, urinary tract and bloodstream. Medical devices, such as catheters and intravenous needles, and surgical or medical procedures can also sometimes spread bacteria to the bloodstream.

If you have cancer, you are at a greater risk of getting sepsis. This is because having cancer and some cancer treatments can weaken the immune system. A weakened immune system makes it harder for your body to fight infections. If you have leukemia or another blood cancer and are receiving chemotherapy, your healthcare team may prescribe antibiotics to prevent sepsis.


Symptoms of sepsis include:

  • confusion
  • feeling less alert
  • feeling restless
  • fever
  • chills and shivering
  • warm skin
  • fast heartbeat
  • fast breathing
  • low blood pressure
  • skin rash

Other symptoms can develop as sepsis gets worse, including:

  • below-normal temperature
  • cool, pale and clammy arms or legs
  • bruising or bleeding
  • low or no urine output
  • coma

Report symptoms to your doctor or healthcare team right away.


Your doctor will try to find the cause of the infection and how severe your sepsis is. Sepsis is usually diagnosed by:

  • a physical exam
  • a complete blood count (CBC)
  • blood cultures to identify what caused the infection
  • blood gases to measure the level of oxygen in the blood
  • blood chemistry tests
  • a urinalysis and urine culture (especially in people with urinary catheters)
  • cultures of mouth sores, skin sores, stool or intravenous sites
  • a chest x-ray
  • an electrocardiogram (ECG)
  • a CT scan

Find out more about these tests and procedures.

Treating sepsis and septic shock

Once sepsis or septic shock is diagnosed, your healthcare team will treat it. The type of treatment you receive will depend on the severity of sepsis and what caused the infection. People with septic shock are usually treated in an intensive care unit (ICU). The healthcare team will monitor you closely and check your blood pressure, heart rate and breathing often.

The following treatments are used for sepsis and septic shock.

Increase blood pressure

You will be given fluids through a needle into a vein (intravenously) to raise your blood pressure. You may also be given medicines to raise your blood pressure.

If your blood pressure doesn't increase with intravenous fluids and medicines, you may be given corticosteroids. These are drugs that can help reduce swelling and lower the body's immune response.

Treat infection

You may be given intravenous antibiotics to treat the infection that caused sepsis. The type of antibiotic used depends on the type of bacteria present. You may be given 2 or more antibiotics until the healthcare team finds out what caused the infection.

If the healthcare team thinks that the infection was caused by a catheter, they will remove it. You may also need to have surgery to drain an abscess or remove dead tissue that could have started the infection.

Medical treatments

You may be given oxygen therapy if you have trouble breathing. If there are serious lung problems, you may be put on a ventilator.

If septic shock damages your kidneys, you may need dialysis. Dialysis removes wastes from the blood when the kidneys don't work properly.

Expert review and references

  • John Granton, BSc MD FRCPC

Medical disclaimer

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