The unexpected connection between infection and heart disease.

The connection: between heart disease and infection

A growing body of research shows that infections, both viral and bacterial, raise the short-term risk of heart disease and stroke. The link is strongest with chest (respiratory) infections such as influenza and pneumonia, and the risk tends to be greater when the infection is more severe. Importantly, the elevated risk can persist for weeks after the infection itself has resolved (Musher et al., New England Journal of Medicine, 2019; Nguyen et al., Cardiovascular Research, 2025).

The impact of influenza

Heart attacks and strokes tend to cluster during influenza season, and this timing is more than coincidence. Studies that track infections and hospital admissions over time consistently find spikes in cardiovascular events during and shortly after flu activity. One meta-analysis estimated that influenza raises the risk of heart attack roughly five-fold and stroke nearly five-fold in the weeks after infection (Nguyen et al., Cardiovascular Research, 2025; Warren-Gash et al., European Respiratory Journal, 2018).

Warning signs

Common symptoms of a heart attack or stroke still apply: chest pain or pressure, shortness of breath, or sudden weakness, numbness, or difficulty speaking. Some people, particularly women, report unusual fatigue in the days or weeks beforehand, though fatigue is nonspecific and is not a reliable predictor on its own (Blakeman et al., Journal of Clinical Nursing, 2020). Anyone who feels acutely unwell after an infection, especially with chest or breathing symptoms, should seek prompt medical attention.

Why infection affects the heart

Infection sets off body-wide inflammation. Inflammatory cells and signaling molecules can destabilize existing cholesterol plaques in the arteries, making them more likely to rupture. At the same time, infection makes the blood more prone to clotting by activating platelets and clotting factors, and some respiratory viruses switch on genes that further promote clot formation. Together, these changes can trigger a heart attack or stroke (Musher et al., New England Journal of Medicine, 2019; Libby et al., Journal of the American College of Cardiology, 2018).

The awareness gap

This connection is well established in the medical literature but not widely known to the public, and vaccination rates remain below target, particularly among adults under 65 and others at risk (Rademacher et al., European Journal of Preventive Cardiology, 2024).

Steps to protect your heart

• Talk with friends and family about the link between infection and cardiovascular risk.

• Stay up to date on vaccines. Influenza vaccination is associated with roughly a 25–37% reduction in major cardiovascular events, and cardiology guidelines now recommend annual flu vaccination to reduce cardiovascular risk (Volpe et al., International Journal of Cardiology, 2026; Heidenreich et al., American College of Cardiology, 2026). Pneumococcal vaccination is also linked to fewer cardiovascular events in older adults, though the evidence is less consistent (Addario et al., GeroScience, 2023).

• COVID-19 vaccination appears to lower the risk of cardiovascular complications after infection as well (Cai et al., JAMA Internal Medicine, 2026).

  
  

The bottom line

Protecting yourself against infection is also a way to protect your heart and blood vessels. Staying current on recommended vaccines, and managing traditional risk factors such as blood pressure, cholesterol, diabetes, and smoking, can reduce preventable cardiovascular risk.

With thanks to the New England Journal of Medicine review "Acute Infection and Myocardial Infarction" (Musher, Abers, and Corrales-Medina, 2019) for informing this discussion.

FAQs

What types of infections are linked to heart disease?

Both viral and bacterial infections are linked to an increased risk of heart disease, with respiratory infections like influenza and pneumonia being the most significant.

How long does the elevated risk of heart disease last after an infection?

The elevated risk can persist for weeks after the infection has resolved.

What are the warning signs of a heart attack or stroke?

Common symptoms include chest pain or pressure, shortness of breath, sudden weakness, numbness, or difficulty speaking. Unusual fatigue may also be a warning sign, particularly in women.

How can I protect my heart from infections?

Stay up to date on vaccinations, discuss the risks with friends and family, and manage traditional cardiovascular risk factors such as blood pressure and cholesterol.

Are vaccinations effective in reducing cardiovascular risks?

Yes, vaccinations such as the influenza vaccine have been shown to significantly reduce the risk of major cardiovascular events.

Further reading- at Preventiononly, we recommend regular vaccination to the ones at risk. To learn more about our methods-go to www.preventiononly.com/about