Researchers dug into health records and found a near-universal pattern: most serious cardiovascular events don’t arrive out of the blue. The team reviewed data from more than 600,000 Korean adults and nearly 1,200 American adults who later experienced heart attacks, strokes, or heart failure, and the results were striking and consistent. Before the crisis, almost everyone had at least one common risk factor.
Nearly 99 percent of people in both groups had at least one of four major risk factors: smoking, high blood pressure, high cholesterol, or elevated blood sugar. These are not exotic or hard-to-detect problems; they’re everyday issues that often build up quietly. That means prevention, not miracles, is the most realistic path to avoid most catastrophic heart events.
“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. Those warning signs are often measurable long before a person ends up in the hospital, which changes how we should think about risk. If you’re surprised by heart disease, you may simply not have been checked.
What the Numbers Reveal and What You Can Do
Most participants didn’t just have one problem; they carried multiple risk factors for years. “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. That clustering multiplies risk and gives doctors more targets for early intervention.
High blood pressure was the standout issue, affecting up to about 96 percent of people in the study, making it the dominant driver of poor outcomes. Smoking, while less common than high blood pressure, still showed up in roughly 68 percent of patients as a current or former habit. These figures make one point loud and clear: reduce these risk factors and you reduce the odds of disaster.
The study didn’t prove direct cause-and-effect for each risk factor and every event, and most of the data came from Korean adults, so results may vary across different populations. Even with those limits, the consistency across ages and sexes adds weight to the message: risk usually existed before the event. Women under 60 were slightly less likely to have a recorded risk factor, but even in that group more than 95 percent had at least one.
Practical prevention is straightforward and actionable, and it starts with common sense medical checks and daily habits. Get enough sleep: adults need about seven to nine hours a night to support heart health, metabolism, and recovery. Keep an eye on weight and aim for a BMI in the healthy range of 18.5 to 25, because excess weight nudges blood pressure, cholesterol, and blood sugar in the wrong direction.
Cholesterol and blood sugar are both easy to monitor with routine blood tests, and they respond well to lifestyle changes and, when needed, medication. Hemoglobin A1C gives a clear view of average blood sugar over several months, and managing that number can cut down on long-term complications. Your doctor can help interpret results and recommend diet, exercise, or meds if numbers are outside target ranges.
High blood pressure deserves special attention because of how common and harmful it is. Aim to keep blood pressure within recommended ranges through diet, exercise, stress reduction, and medication when required. High blood pressure is typically defined as systolic readings of 130 to 139 mm Hg or diastolic readings of 80 to 89 mm Hg, so even modest elevations matter.
Stopping smoking is one of the single most impactful choices a person can make for heart health, and quitting helps quickly reduce risk. Many people think they’re healthy until the first emergency arrives, which is often the moment they learn otherwise. Regular checkups and honest conversations with a clinician can catch problems early, when they are far easier to manage.
“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. That observation reframes how we view prevention: these are not mysteries, they are missed opportunities. Treatment is possible, but avoiding the problem in the first place is smarter and less costly.
Talk to your doctor proactively rather than waiting for a crisis to force the conversation. “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. Early, steady attention to blood pressure, cholesterol, blood sugar, sleep, weight, and smoking status is the way to keep your heart out of the emergency room.
