Sepsis & the Flu
Woman with the flu holder a thermometer

Sepsis can be a serious and life-threatening complication of the flu. Sepsis is the body’s extreme reaction to infection. The body attacks its own organs and tissues, which can lead to tissue damage, organ failure, and death. Any type of infection, including the flu (influenza) can cause sepsis. Sepsis can result from a bacterial, viral, and fungal infection.

About the Flu.

Influenza, commonly known as the flu, is a contagious respiratory illness caused by influenza viruses. It affects the nose, throat, and sometimes the lungs. The flu can range from mild to severe and can result in serious health complications, especially in vulnerable populations such as the elderly, young children, pregnant women, and individuals with compromised immune systems.

Sepsis & the Flu.

While the flu primarily affects the respiratory system, it can sometimes lead to secondary bacterial infections or exacerbate existing health conditions. When the flu virus weakens the immune system and causes damage to the respiratory tract, bacteria can invade the body more easily, leading to bacterial pneumonia or other infections.

If these secondary bacterial infections spread into the bloodstream, they can trigger sepsis. Additionally, the immune system’s response to the flu can sometimes become dysregulated, causing an excessive inflammatory response throughout the body, leading to sepsis.

Symptoms of the Flu.

The flu typically comes on suddenly and may include symptoms such as:

  • Fever
  • Chills
  • Cough
  • Sore throat
  • Runny or stuffy nose
  • Muscle or body aches
  • Headaches, fatigue
  • Sometimes vomiting and diarrhea

Symptoms of Sepsis.

Sepsis can develop rapidly and may present with the following symptoms:

  • Fever or low body temperature
  • Rapid heart rate (tachycardia) and rapid breathing (tachypnea)
  • Confusion or disorientation
  • Extreme fatigue or weakness
  • Chills or shivering
  • Reduced urine output
  • Abdominal pain, nausea or vomiting
  • Skin rash or discoloration
  • Difficulty breathing
  • Low blood pressure
  • Elevated white blood cell count
  • Elevated lactate levels

If you detect even a few of these symptoms, seek medical help immediately and ask, “could it be sepsis?”

Download are share the signs of sepsis from our Resources page

Learn how to spot the difference between sepsis and the flu: Sepsis or Flu? How to Tell the Difference.


Flu is caused by the influenza virus. Most often, the virus is transmitted when an infected person coughs or breathes on another person who ingests the tiny airborne droplets. Touching something that has the virus on it and then touching your mouth can also lead to infection. Flu most commonly occurs during the winter months.

Risk Factors for the Flu.

  • Age: Both the very young and the elderly are more vulnerable
  • Weakened immune system: Individuals with chronic illnesses, immunocompromised conditions, or on immunosuppressive medications
  • Pregnancy: They experience changes in their immune function during pregnancy
  • Chronic medical conditions: Such as diabetes, heart disease, lung disease, or kidney disease
  • Obesity: People with obesity may be at higher risk of severe flu complications
  • Being a residents of long-term care facilities: Outbreaks of flu can be severe in these settings


Sepsis is diagnosed by a medical professional following a physical examination, evaluation of medical history and blood tests.

Treatment for the Flu.

For mild flu, rest, staying hydrated, and over-the-counter medications to relieve symptoms are usually sufficient for mild cases of the flu.

For severe flu cases, antiviral medications may be prescribed to reduce the severity and duration of flu symptoms, especially in high-risk individuals.

Treatment for Sepsis.

Immediate medical attention is crucial. Treatment often involves hospitalization, intravenous antibiotics, fluids, and other supportive measures to stabilize the patient.

Flu Prevention.

  • Annual flu vaccination: The flu shot is the most effective way to prevent the flu and its complications.
  • Hygiene measures: Regular handwashing, covering mouth and nose when sneezing or coughing, and avoiding close contact with sick individuals can reduce the risk of infection.
  • Strengthening the immune system: Adopting a healthy lifestyle with balanced nutrition, regular exercise, and adequate sleep can bolster the immune system.


Michael Dowling

Michael Dowling

The bulk of mortality in a hospital system comes from sepsis. It’s not good enough to have any percentage of infection. It has to be zero.

President & CEO, Northwell Health