Sepsis is a life threatening illness that develops when an existing infection triggers an extreme immune system response in your body.

When you experience an infection, your immune system releases proteins and other chemicals to fight it. Sepsis occurs when this response gets out of control, triggering extensive inflammation.

There are approximately 1.7 million cases of sepsis each year in the United States, according to the Centers for Disease Control and Prevention (CDC). It’s also responsible for nearly 350,000 deaths.

Keep reading to learn more about the symptoms, types, and causes of sepsis, as well as how it’s treated.

There are three stages of sepsis:

  • Sepsis: An infection gets into your bloodstream and causes inflammation in your body.
  • Severe sepsis: The infection and inflammation is severe enough to start affecting organ function.
  • Septic shock: This severe complication of sepsis causes a significant drop in blood pressure and may lead to serious complications like:

While sepsis often occurs in hospital settings, it can also happen in other locations. In some cases, you might not even know you have an infection that could potentially lead to sepsis.

It’s important to seek immediate medical attention if you have any symptoms of sepsis. The earlier you seek treatment, the greater chance you have of recovering.

According to the World Health Organization (WHO), some common symptoms of sepsis may include:

It’s possible to mistake these symptoms for those of another condition, like pneumonia, COVID-19, or cancer.

Symptoms of severe sepsis

Severe sepsis is characterized by organ failure and may be accompanied by the following symptoms:

This could advance very quickly to septic shock, which may be life threatening.

Some symptoms of severe sepsis and septic shock can overlap, but a key sign of septic shock is low blood pressure.

Symptoms in children

Neonatal sepsis occurs when a baby gets a blood infection within the first month of life.

Some symptoms may include:

Sepsis is usually caused by a bacterial infection. The most common include:

According to the CDC, fungal and viral infections may also cause sepsis, including COVID-19 and the flu.

Anyone who gets an infection is at risk of developing sepsis.

However, researchers and healthcare organizations have identified several risk factors associated with sepsis, including:

  • being age 65 years and older
  • being younger than 1 year old
  • being pregnant or chestfeeding
  • having a weakened immune system, such as if you’re undergoing chemotherapy treatment for cancer
  • having certain health conditions, such as diabetes, liver disease, kidney disease, and cancer
  • taking certain medications, such as corticosteroids
  • recently having surgery
  • being in intensive care units (ICUs)
  • being exposed to invasive devices, like intravenous catheters or breathing tubes

A doctor will examine your symptoms and order tests to help diagnose the cause and severity of your infection.

One of the first tests is a blood test, which could help them check for:

A doctor may also order the following tests to check for bacteria in your body or to view different organs:

Doctors use two sets of criteria to determine the severity of sepsis.

One set is for systemic inflammatory response syndrome (SIRS). SIRS is defined when you meet two or more of the following criteria:

  • fever of more than 100.4°F (38°C) or less than 96.8°F (36°C)
  • heart rate of more than 90 beats per minute
  • respiratory rate of more than 20 breaths per minute or arterial carbon dioxide tension (PaCO2) of less than 32 millimeters of mercury (mm Hg)
  • abnormal white blood cell count

Another tool is the quick sequential organ failure assessment (qSOFA). It uses the results of three criteria:

  • low blood pressure reading (systolic blood pressure of less than 100 mm Hg)
  • high respiratory rate (greater than 22 breaths per minute)
  • Glasgow coma scale score of 14 or less to determine your level of consciousness

A positive qSOFA occurs when two or more of the above measurements are abnormal. Some physicians prefer using qSOFA because, unlike the SIRS criteria, qSOFA doesn’t require laboratory tests.

The results of either of these assessments will help a doctor determine the best course of treatment.

Sepsis can quickly progress to septic shock and death if it’s left untreated. As such, it’s important to start treatment with antibiotics as soon as possible after receiving a diagnosis.

Doctors may also use the following medications to help treat sepsis:

  • medications to increase blood pressure (vasopressors)
  • insulin to stabilize blood sugar
  • corticosteroids to reduce inflammation
  • pain relievers to help with discomfort

Severe sepsis may also require large amounts of IV fluids and a respirator for breathing. If your kidneys are affected, you may require dialysis to help filter your blood.

In some cases, surgery may be needed to remove the source of an infection. This may include draining a pus-filled abscess or removing infected tissue.

Recovering from sepsis depends on the severity of your condition and any pre-existing health issues you might have.

According to the UK Sepsis Trust, around 4 in 10 people experience effects from sepsis.

When you return home after receiving treatment in the hospital for sepsis, you may experience physical, cognitive, and emotional symptoms that may last several months. These may include:

Many people fully recover, but others report lasting effects, which is known as post-sepsis syndrome (PSS). PSS may affect up to 1 in 2 sepsis survivors, according to the Sepsis Alliance.

The CDC notes that PSS may cause long-term effects like:

The best way to prevent sepsis is to treat infections promptly and to practice good hygiene, such as proper wound care, handwashing, and bathing regularly.

Preventing infections is the next best way to prevent sepsis. This may include staying up to date with vaccinations and managing chronic conditions, such as taking medications.

It’s important to get immediate medical attention if you experience any symptoms of sepsis. Early diagnosis and treatment could help prevent any complications.

Complications of sepsis are more likely to occur in severe cases of sepsis. They may include:

How long can you survive with sepsis?

The life expectancy for sepsis will depend on the severity of the infection and how early you receive treatment. Many people will survive and experience few complications. That said, a 2020 review found that the mortality rate for sepsis after 90 days was 32.2% and 38.5% for septic shock.

How quickly can an infection turn to sepsis?

The progression from infection to sepsis depends on many factors, such as the type and location of the infection, and how quickly you receive treatment.

For instance, a 2013 study found that people with soft tissue infections were 9% less likely to progress to sepsis or a more severe stage within 7 days than people with urinary tract infections. People with abdominal infections were 32% more likely to progress to sepsis within this timeframe.

Early treatment is vital for slowing down the progression of sepsis. According to the Sepsis Alliance, the risk of sepsis progressing to septic shock and even death rises by up to 9% for each hour without treatment.

Is sepsis contagious?

No, sepsis isn’t contagious. However, the pathogens responsible for the original infection, like viral pneumonia or COVID-19, may be contagious.

Sepsis is a life threatening illness that occurs when your body’s immune system overreacts to an infection.

People at the highest risk of sepsis include newborns, older adults, and people with pre-existing health conditions.

Sepsis is a medical emergency and may cause symptoms like fever, chills, a rapid heart rate, confusion, and difficulty breathing.

Get immediate medical attention if you suspect you have sepsis, especially if you have a known infection.