Heart Disease Can Begin Decades Before Symptoms

Heart disease can develop silently long before symptoms or a diagnosis. In a study published in The New England Journal of Medicine, researchers found atherosclerotic plaque even in some participants in their 20s who had no known cardiovascular disease. The finding does not predict who will have a heart attack, but it makes a case for recognizing and addressing cardiovascular risk factors earlier.  

We often judge heart risk by the chance of a heart attack in the next ten years. For a young adult, that chance may be very low. But a low ten-year risk does not rule out problems over the decades that follow.

Those decades matter. Arteries are exposed year after year to cholesterol levels, blood pressure, smoking, and other factors. A risk that seems unimportant today may deserve attention if it persists.

The response is neither fear nor a scan for everyone. It begins with knowing your risk factors and family history, following up on concerning results, and acting while there is time to protect your future health. The most valuable years for prevention may be the years when everything feels right.

Short-term risk versus long-term health

We often confuse short-term risk with long-term health. A young adult can have a very low chance of a heart attack in the next decade even when changes in the arteries have already begun.

What researchers found in young adults

The REACT study was designed to look for silent atherosclerosis across different adult age groups. Researchers examined 16,808 adults aged 18 to 70 in Denmark and Spain who had no known cardiovascular disease. Using imaging, they looked for plaque in arteries supplying the heart, neck, and legs.  

They found atherosclerotic plaque even among some participants aged 18–29: 8.7% of men and 6.7% of women. In younger adults, plaque was generally limited to one vascular area, most often an artery outside the heart. The amount of plaque and the number of affected areas increased with age. The study gives us a view of a process that can begin long before it causes symptoms.

The years of exposure matter

An elevated cholesterol level at 25 does not mean a heart attack is close. But arteries are exposed to that level year after year. A 2025 analysis of more than 4,300 participants in the CARDIA study linked greater exposure to cholesterol-carrying particles during young adulthood with cardiovascular disease after age 40.  

Cholesterol is one part of the picture. High blood pressure, smoking, and diabetes can also affect cardiovascular health over time. This changes the question we ask: alongside “How likely is a heart attack soon?” we need to ask “Which risk factors could continue affecting this person for decades?”

Early plaque is not a prediction

The REACT study shows that atherosclerosis can be detected in some young adults. It does not tell us whether a particular plaque will grow, remain stable, or ever cause a problem. Detecting plaque at one point in time is different from predicting a heart attack.  

The study also does not establish that every young adult needs an artery scan. What a finding means for one person depends on the broader picture, including their medical history and cardiovascular risk. The value of REACT study is that it makes the early, silent stages of atherosclerosis visible; it does not provide a forecast for each participant.

Give prevention more time to work

For young adults, prevention begins with an understanding of blood pressure, cholesterol levels, and any family history of early heart disease or stroke. Persistently elevated results deserve follow-up rather than being set aside until middle age. The 2026 ACC/AHA guideline on dyslipidemia emphasizes early attention to cardiovascular health and gives particular consideration to young adults with markedly elevated LDL cholesterol or a strong family history of premature cardiovascular disease.  

Everyday habits matter, too: regular physical activity, an eating pattern that supports heart health, and avoiding tobacco and nicotine. When blood pressure, cholesterol, or blood sugar is high, addressing it with a clinician before symptoms appear can reduce the years of exposure. These priorities are reflected in the American Heart Association’s measures of cardiovascular health.  

Final thoughts

Heart disease does not necessarily begin when it is diagnosed. Changes in the arteries may develop quietly for years, which makes early attention to cardiovascular health worthwhile.

Finding plaque early does not mean a heart attack is inevitable, or that everyone needs a scan. It reinforces the importance of assessing cholesterol, blood pressure, and smoking early, while taking family history into account.

The years before symptoms or a diagnosis offer an opportunity: to identify risk factors, act on what we can change, and protect what comes later.