Influenza (Flu)

Influenza, the flu, is a common, very infectious viral infection. Over the years, many people have used the term “the flu” to describe anything from a stomach bug to a bout of food poisoning, but influenza is a respiratory illness and doesn’t have anything to do with the gastrointestinal system – the system that runs from your mouth to your rectum.

People who are infected with an influenza virus may develop sepsis. Sometimes incorrectly called blood poisoning, sepsis is the body’s life-threatening response to infection. Sepsis kills and disables millions and requires early suspicion and rapid treatment for survival.

Sepsis and septic shock can result from an infection anywhere in the body, such as pneumonia, influenza, or urinary tract infections. Worldwide, one-third of people who develop sepsis die. Many who do survive are left with life-changing effects, such as post-traumatic stress disorder (PTSD), chronic pain and fatigue, organ dysfunction (organs don’t work properly) and/or amputations.

Doctors have found that rates of sepsis and severe sepsis tend to go up during so-called flu season.

Influenza and COVID-19

Influenza and COVID-19 are two separate viruses, but they both affect the respiratory system. Their initial symptoms can be quite similar: cough, fever, aches and pains. Experts encourage people to get their seasonal flu vaccine as usual to avoid a so-called “twindemic.” They are concerned that influenza cases and COVID-19 cases can peak at the same time during so-called flu season.

The fears are two-fold. If you develop symptoms that overlap the two infections, doctors won’t know which one you may have. You will have to undergo COVID-19 testing and the medical staff will have to take the necessary precautions until COVID-19 is ruled out. The second issue is if you get the flu, your immunity drops as your body fights the infection. This makes you more vulnerable to catching COVID-19 if you are exposed to it. It is possible to have both infections at the same time.

What is influenza?

There are different types of influenza. There is the annual seasonal influenza and others, such as the H1N1 influenza, avian flu, and swine flu.
There are three separate types of viruses that affect humans:

  • Type A: Type A influenzas affect both people and animals, such as birds. The animals help spread the virus, which can be very serious. The type A flus are the ones that cause most of the flu pandemics or epidemics. In 1918, the world was hit with the flu outbreak which killed millions of people. It was feared in 2009 that the H1N1 virus would have similar outcomes.
  • Type B: Type B influenzas do not infect animals and do not cause epidemics or pandemics, but they still can cause serious harm. 
  • Type C: Type C influenzas are milder than either types A or B. They do not cause epidemics or pandemics and they only affect humans.

The viruses that cause influenza are not static, which means they do not stay the same. They can change and mutate, turning into new viruses. This is why if you catch the flu one year, you can catch it again the next – because the virus has changed enough from the year before that your body doesn’t recognize it.

The types of influenza, such as H1N1, are named by their make up. There are 16 subtypes of hemagglutinin (the “H”) and nine subtypes of neuraminidase (the “N”). These are proteins that help make up the virus. Therefore, the name of the virus is given by which humagglutinin and which neuraminidase are present.

The most commonly known influenza is the seasonal one. This is a different virus that moves around the world each year. The most recent statistics available for influenza are from the 2018/19 flu season. The CDC estimates that the seasonal flu killed an estimated 34,200 people during that season.Although this was down from the 61,000 flu-related deaths the year before, 34,200 people represent the number of fans who can fit in Progressive Stadium in Cleveland, Ohio, home of Major League Baseball’s Cleveland Guardians.

How do you get influenza?

Influenza is a highly contagious respiratory infection. It is caught when the virus comes in contact with the mucus membranes in your nose. This could be contamination of the air (someone next to you sneezing) or by touch. Someone who has the flu touches his nose or mouth and then touches an object, which you then pick up. If you don’t wash your hands, at some point if you touch your mouth or nose, you have brought the virus close enough to infect yourself.

What are the symptoms of influenza?

It’s important to understand the difference between influenza and colds. With the common cold, symptoms usually come on gradually, but with the flu, the symptoms appear quite suddenly. They can include:

  • Fever (although not always present) and chills
  • Cough
  • Sore throat
  • Runny or stuffy nose
  • Muscle aches, body aches
  • Headache, sometimes severe
  • Fatigue
  • Vomiting and diarrhea, more likely in young children

Is there treatment for the flu?

If you are like most people, a bout with influenza may hit you hard. But after a week or two, you will begin to recover, although it could take several weeks before you feel like you are back to normal. However, for some people the flu can cause serious complications and even death. Complications may range from secondary infections (infections that occur as a result of the flu) to dehydration to sepsis.

If you think you have the flu, it’s always best to check with your doctor or nurse practitioner to see if you should be treated with antiviral medications. If you are not a high risk of developing complications, your doctor may tell you just to manage the flu at home, but to go to the emergency if you seem to get worse or develop new symptoms.

At-home care of the flu means managing the symptoms and preventing dehydration:

  • Rest. Stay in bed to let your body restore itself and to prevent spreading your infection
  • Drink a lot of fluids. It is easy to become dehydrated when you have the flu. These should be water and clear fluids, such as broths.
  • Take over-the-counter medications, such as acetaminophen or ibuprofen if you are allowed to. If the sick person is a child or teen, do not give aspirin because of a rare, but fatal complication that can occur, called Reyes syndrome. Over-the-counter cold-and-flu remedies are not recommended for children under the age of six years, as per the FDA.

Anyone who has the flu and develops the following signs, should seek medical help as soon as possible, regardless of age or usual state of health:

  • Difficulty breathing or shortness of breath
  • Pain or pressure in the chest or abdomen
  • Sudden dizziness
  • Confusion
  • Severe or persistent vomiting
  • Flu-like symptoms improve but then return with fever and worse cough
  • High fever for more than three days

If you are at high risk for developing complications, your doctor may want you to take antiviral medications, such as Tamiflu. These medications must be taken within the first 72 hours of exposure to the virus for them to be effective. You may still feel ill before they begin to take effect.

Can the flu be prevented?

Yes, influenza can be prevented with a few simple precautions and, in many cases, with a vaccination.


  • Hand washing is the number one weapon against influenza. Washing your hands after touching your face if you have the flu or after touching potentially contaminated objects (such as door handles, public phones) has been proven to effectively reduce the chances of passing on or developing the flu.
  • Sneezing or coughing into your elbow is a good way to reduce transmission of the flu virus. Unlike sneezing or coughing into your hand, your elbow won’t touch common objects that will be touched by others.
  • If you have the flu, avoid others while you have symptoms and for 24 hours after the symptoms have gone.
  • Get your annual flu vaccination. Every year, a new vaccine is developed based on the information about the new influenza strain that is circling the globe. Getting a vaccination is your best protection, although it may not be 100%. If you cannot get the vaccine for health reasons, encourage your family members, friends, and coworkers to be vaccinated. If they reduce their risk of getting the flu, your risk of catching it becomes lower.Eat a healthy diet. Malnutrition, not consuming enough nutrients for your needs, can lower your body’s ability to fight infection.

Updated March 17, 2022.


Sepsis and Flu
Information Guide


Flu-Related Faces of Sepsis

Read Personal Stories of Sepsis and Influenza (Flu)

Lochlin DeSantis

On January 20th of 2020 our 5-year-old son Lochlin passed away from flu – sepsis. (Sepsis and Influenza) Saturday he was tired with a low grade fever and some minor body aches. By Sunday he was feeling much better and was up playing with his brothers, until Sunday night he took a turn for the worst. We took him to an urgent care where he was diagnosed with influenza type A and mild dehydration. Monday afternoon January 20th, 2020 he passed away from flu – sepsis. Since then it has become our mission to spread the love Lochlin had for ... Read Full Story

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Joshua Roy

On Oct 13th 2019, my 13 year old son, Josh became very ill; only complaining of a sore throat and fever the day prior. Josh went unresponsive in our home, an ambulance came and took him to the closest hospital where the doctor immediately intubated him and sent him on a helicopter to Riley Hospital for Children. The outlook seemed to be grim. Josh’s diagnoses was influenza b, necrotizing staph pneumonia, viral myocarditis, and septic shock. (Sepsis and Influenza, Sepsis and Pneumonia, Sepsis and Viral Infections, Sepsis and Septic Shock) Our boy wasn’t expected to live. The night he arrived ... Read Full Story

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Ronit Chernitzky

Hello, I am a 43 year old woman, born in Mexico, but live in Panama. Six years ago, I had flu-like symptoms. I went to the doctor and was sent to the emergency room, only to be discharged six hours later. I went home, and my husband, who arrived a few hours later, saw me unconscious in bed. He took me back to the hospital where I was taken directly to the ICU, put on a respirator, and put into an induced coma. I had developed severe pneumonia, and my organs started to fail. (Sepsis and Pneumonia) I was on ... Read Full Story

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Paul Carney

On the 1st of March, 2019, I was at work and became aware of a tickle in my throat, and thought that I was starting to come down with a cold. As the days went on, my cold got worse. Fever and flu-like symptoms started, and I made the massive error in thinking that if I rested in bed, I would give myself time to get rid of it naturally. Unfortunately, I had contracted a mutated version of the swine flu, but I wasn’t aware of this at the time. (Sepsis and Influenza) My condition worsened and the cough turned ... Read Full Story

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Betty Wattenbarger

My daughter Betty Wattenbarger died from flu complicated by sepsis and pneumonia. (Sepsis and Influenza, Sepsis and Pneumonia) She was 7. We were at a pediatric urgent care the day before her death and the APN on staff diagnosed her with flu and said her lungs were clear. The next morning she died. She was bleeding internally from sepsis and pneumonia. The nurse missed her having nearly 1/3 of a cup of fluid in her left lung. The nurse did not do a PCT test l, X-ray or any other diagnostic. We know now after her death that she was ... Read Full Story

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Influenza (Flu)

Influenza, the flu, is a common, very infectious viral infection. Over the years, many people have used the term “the flu” to describe anything from a stomach bug to a bout of food poisoning, but influenza is a respiratory illness and doesn’t have anything to do with the gastrointestinal system – the system that runs from your mouth to your rectum.