Can the Flu Trigger a Heart Attack?

What can the flu do to you? If you have heart disease, one answer may be life-threatening.

Influenza-related stress on your body can launch a negative chain of events that builds toward a heart attack. And research shows that people with heart disease are nearly 10 times more likely to have a heart attack after coming down with the flu.

To explain the connection, we turn to infectious disease expert Kristin Englund, MD.

How the flu can affect your heart

If you get the flu, your immune system moves aggressively to fight off the virus. The response leads to internal inflammation, which can elevate your blood pressure and put extra stress on your heart.

Plaque buildup (a waxy, fatty substance) in arteries becomes increasingly vulnerable to ruptures in this situation. As the plaque weakens and breaks, artery-clogging clots can form and disrupt blood flow to your heart — a blockage could trigger a heart attack.

Anyone with an existing heart issue is more likely to have their cardiovascular system overwhelmed by the effects of the flu, says Dr. Englund.

“Fighting off the infection can put a lot of stress on the heart,” she adds. “If you have an underlying health issue, such as heart disease, complications from the flu can cascade into something much worse.”

Can the flu cause other serious health issues?

Absolutely — and that’s a reality seen through statistics from the U.S. Centers for Disease Control and Prevention (CDC).

Between 2010 and 2020, the flu hospitalized between 140,000 and 710,000 people in the U.S. annually, according to estimates from the CDC. Deaths tied to the flu ranged from 12,000 to 52,000 over the same period.

“People often underestimate the flu,” notes Dr. Englund. “It’s not just a cold, and it can be deadly.”

Possible complications from the flu include:

• Pneumonia and bacterial pneumonia, which can lead to respiratory failure. “This is the No. 1 complication,” says Dr. Englund. “If people’s pneumonia gets bad enough, they’ll often end up on a ventilator.”
• Additional cardiac issues such as myocarditis (inflammation of your heart muscle) or an arrhythmia.
• Stroke, through the same clotting process that can cause a heart attack.
• Encephalopathy (severe central nervous system damage).

Who’s most at risk for flu complications?

You’re at high risk for developing flu complications if you have:

• Other severe health problems, including heart disease.
• A compromised immune system due to age (either very young or elderly) or pregnancy.

Tips to prevent flu-related heart issues

Be proactive in preventing problems with the flu by doing the following:

• Get your flu shot. Getting a seasonal flu shot can significantly lower your risk of having a heart attack or cardiac arrest if you’re in a high-risk group, according to research reported by the American Heart Association.
• Avoid contact with people who are sick. No handshaking during flu season. Stay away from other people’s bodily fluids. Practicing good hand hygiene with frequent handwashing is important as well.
• Keep your heart in check. If you have heart disease, manage your condition carefully with medication, diet and exercise as recommended by your doctor. These preventive actions will help keep your overall immune system strong. If your heart condition is stable and you end up with the flu, chances are, you’ll experience fewer, less severe complications.
• Don’t dismiss flu-like symptoms. Especially if you’re in a high-risk group, talk to your doctor right away. Timing is important. Tamiflu® is a prescription medication that may mildly shorten the duration of the flu if taken within a few days of the onset of symptoms.
• Take time to rest. If you have flu-like symptoms, take time to rest and drink plenty of fluids. The longer you stay at home and rest, the faster you’ll recover.