99 Percent of Heart Attacks and Strokes Are Tied to Preventable Health Issues
A new study points to 4 factors that do the most to raise the risk of serious cardiovascular problems, all modifiable through lifestyle changes or medication.
Just about every heart attack, stroke, and case of heart failure is associated with at least one cardiovascular risk factor, a new study suggests.
Researchers came to this conclusion by examining health records for more than 600,000 Korean adults and almost 1,200 American adults who had one of these cardiovascular issues. Before things reached a crisis point, 99 percent of participants in both groups had developed at least one of four common cardiovascular disease risk factors: smoking, high blood pressure, elevated cholesterol, or high blood sugar.
“We often think that heart disease can happen without warning, but there is almost always a warning sign,” says study coauthor Sadiya S. Khan, MD, a professor of cardiovascular epidemiology at the Northwestern University Feinberg School of Medicine in Chicago.
Many People in the Study Unknowingly Had Multiple Risk Factors
Many people who thought they were perfectly healthy right up until they had heart failure, a heart attack, or a stroke did not know they were at risk, says lead study author Hokyou Lee, MD, PhD, an associate professor of preventive medicine at Yonsei University College of Medicine in Seoul, Korea.
“More importantly, these risk factors rarely existed alone,” Dr. Lee says, noting that more than 9 in 10 study participants had two or more risk factors: 93 percent of the Koreans and 97 percent of the Americans.
Study findings, published in the Journal of the American College of Cardiology, were consistent across age groups and applied to both women and men.
Women under 60 years old were the least likely to have at least one risk factor — but even in this group, more than 95 percent of participants did, the study found.
Don’t Sleep on High Blood Pressure
High blood pressure was the most common risk factor in the study, impacting up to about 96 percent of participants.
A current or former smoking habit was the least common risk factor, prevalent among about 68 percent of patients.
The study wasn’t designed to prove whether or how common heart disease risk factors might directly cause events like heart failure, heart attacks, or stroke. It’s also possible that results based primarily on Korean adults might not reflect what would happen for people from other racial or ethnic groups.
Even so, the findings underscore that prevention is most definitely possible for many people, says Yu Chen, PhD, MPH, an epidemiology professor at the New York University Grossman School of Medicine who wasn’t involved in the new study.
“The most striking result is that almost every case of heart disease, stroke, or heart failure happened in people who already had at least one common risk factor,” Dr. Chen says. “It shows these diseases rarely occur out of the blue.”
How to Reduce Your Risk of Heart Attack, Heart Failure, and Stroke
There are straightforward things you can do to reduce your risk of heart failure, heart attack, and stroke, according to the American Heart Association, including:
Get enough sleep. Adults should aim for an average of seven to nine hours of sleep per night.
Aim for a healthy weight. Try to achieve and maintain a body mass index (BMI) between 18.5 and 25. There are many free BMI calculators online.
Manage cholesterol. Your doctor can check your cholesterol levels with a simple blood test. If your numbers aren't where they need to be, diet, exercise, and medication all can help.
Manage blood sugar. There are blood tests for so-called hemoglobin A1C levels, which reflect average blood sugar levels over about three months. Your doctor can give you personalized advice to keep this in a healthy range.
Bring down high blood pressure Try to keep your blood pressure within the recommended range; lifestyle changes and medication can help you get there. High blood pressure is defined as 130 to 139 mm Hg systolic pressure (the top number in a reading) or 80 to 89 mm Hg diastolic pressure (bottom number).
“Instead of trying to treat risk factors once they develop, or treat heart disease after it develops, talking to your doctor proactively is an important step because you can discuss options to reduce your risk for ever developing the condition,” Dr. Khan says.
EDITORIAL SOURCES
Everyday Health follows strict sourcing guidelines to ensure the accuracy of its content, outlined in our editorial policy. We use only trustworthy sources, including peer-reviewed studies, board-certified medical experts, patients with lived experience, and information from top institutions.
Resources
Lee H et al. Very High Prevalence of Nonoptimally Controlled Traditional Risk Factors at the Onset of Cardiovascular Disease. Journal of the American College of Cardiology. September 29, 2025.
Tom Gavin joined Everyday Health as copy chief in 2022 after a lengthy stint as a freelance copy editor. He has a bachelor's degree in psychology from College of the Holy Cross.
Prior to working for Everyday Health, he wrote, edited, copyedited, and fact-checked for books, magazines, and digital content covering a range of topics, including women's health, lifestyle, recipes, restaurant reviews, travel, and more. His clients have included Frommer's, Time-Life, and Google, among others.
He lives in Brooklyn, New York, where he likes to spend his time making music, fixing too-old electronics, and having fun with his family and the dog who has taken up residence in their home.
Lisa Rapaport is a journalist with more than 20 years of experience on the health beat as a writer and editor. She holds a master’s degree from the UC Berkeley Graduate School of Journalism and spent a year as a Knight-Wallace journalism fellow at the University of Michigan. Her work has appeared in dozens of local and national media outlets, including Reuters, Bloomberg, WNYC, The Washington Post,Los Angeles Times, Scientific American, San Jose Mercury News, Oakland Tribune, Huffington Post, Yahoo! News, The Sacramento Bee, and The Buffalo News.
