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Here’s How Dangerous the Flu Can Be

Influenza puts stress on your body and can lead to serious conditions like pneumonia or stroke

Woman with protective face mask huddling on floor while flu spores float around in the air.

Newer illnesses like COVID-19 may grab headlines, but old-and-familiar ailments such as influenza, or the flu, remain a serious health concern — a fact that many might learn during the upcoming flu season.


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For example, in the U.S. from October 1, 2022 through April 30, 2023, the U.S. Centers for Disease Control and Prevention (CDC) estimated that there were 27 to 54 million flu illnesses, with 300,000 to 650,000 flu hospitalizations — and 19,000 to 58,000 deaths related to the flu.

Yet despite those numbers, the flu often gets talked about as if it’s little more than the sniffles. That’s a serious underestimation of the illness, cautions infectious disease specialist Kristin Englund, MD.

“It’s not a common cold,” stresses Dr. Englund. “The flu taxes your body. There’s a lot of stress put on your system as it works to fight off the infection — and that can lead to all sorts of complications.”

How dangerous is the flu?

So, why is influenza sometimes mislabeled as a cold? Well, the viruses share symptoms such as a cough, fever and an overall cruddy feeling. But with the flu, symptoms often hit harder and last longer.

“Perfectly healthy people can get severe complications from influenza,” says Dr. Englund. “But if you have any underlying health issues, the risk becomes much greater.”

In severe cases, the flu can lead to:

  • Pneumonia and bacterial pneumonia, which can lead to respiratory failure and ventilator use. Dr. Englund calls pneumonia “the No. 1 complication” seen from the flu.
  • A heart attack or cardiac issues such as myocarditis (inflammation of the heart muscle).
  • Stroke.

Somewhere between 3% and 11% of the U.S. population — which represents millions upon millions of people — get infected with influenza every year, says the CDC. Most will recover within three to seven days, though some may see symptoms last a few weeks.

But your risk for developing severe flu complications increases if you have:

In addition, people at opposite ends of the age spectrum — those younger than 5 years old or older than 65 — tend to be more vulnerable when it comes to flu-related complications. Ditto for those who are pregnant.

Why you should get the flu shot

Avoiding the worst that the flu dishes out begins with avoiding the flu … and the most effective way to do that is to get your flu shot, advises Dr. Englund.

The CDC reports that getting a flu vaccine lowers your risk of getting sick by 40% to 60%. During the 2021-2022 flu season in the U.S., influenza vaccinations prevented an estimated:

  • 1.8 million flu-related illnesses.
  • 1 million medical visits.
  • 22,000 flu-related hospitalizations.
  • 1,000 flu-related deaths.


And even if you do get flu, research shows that a flu shot helps reduce the severity of the illness. A 2021 study found that a flu vaccination lowered the risk of intensive care unit (ICU) admission by 26% and death by 31%.

“It’s a simple shot that’s extraordinarily safe,” states Dr. Englund. “So, why not protect yourself?”

(On a side note, we want to emphasize that the flu shot CANNOT give you the flu.)

Other ways to prevent the flu

Want to keep the flu bug at bay this flu season? Aside from getting your flu shot, consider these tips:

  • Wear a mask. The flu spreads quickly through droplets made by people who cough, sneeze or talk while they’re infected. Wearing a mask over your mouth and nose can help keep you from breathing in the virus.
  • Practicing good hand hygiene. Washing your hands thoroughly limits the possibility of transferring the virus from a surface — a doorknob, perhaps — to your mouth or nose.
  • Avoid contact with people who are sick. Be cautious at large gatherings during the peak months of flu season, typically December through February. Maybe go with a friendly wave or fist bump over a hearty handshake. And stay home if you’re feeling unwell — your friends and family will understand.
  • Live healthy. Taking care of your overall health with diet and exercise can help strengthen your immune system and fortify your body to fight off infection.

Despite best efforts, it’s still possible you may get the virus. Don’t ignore flu-like symptoms like fever, cough and body aches. Talk to a healthcare provider right away, especially if you’re in a high-risk group.

Quick action could allow you to benefit from antiviral medications, which can lessen flu symptoms and help you bounce back a little more quickly.

Final flu thoughts

The bottom line on the flu? Take it seriously.

“We see so many people in hospitals every year because of influenza,” emphasizes Dr. Englund. “People die from the virus every year, too. It’s not something to ignore, so take the precautions you can to stay healthy.”


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