Atherosclerosis is extraordinarily common. Among adults aged 18 to 92, nearly half (48.2%) have detectable plaque in their carotid arteries alone. When you account for all arterial beds throughout the body, the true number is likely higher. It begins earlier than most people expect, progresses silently for decades, and is the underlying cause of the majority of heart attacks and strokes worldwide.
Overall Prevalence in Adults
A large meta-analysis pooling 92 studies of asymptomatic people between 18 and 65 found that 23% had carotid artery plaque detectable by ultrasound. These were people with no symptoms, no diagnosis, and no reason to suspect a problem. A Finnish study scanning three generations of participants, ages 3 to 92, found the overall prevalence of carotid plaques was 48.2% once children were excluded. No plaques were detected in anyone younger than 18.
These numbers reflect just one artery. Plaque tends to develop in multiple locations simultaneously. Research from the AWHS Study found that femoral artery plaques (in the thigh) were the most common, present in 54% of participants, followed by coronary calcification at 38% and carotid plaques at 34%. The femoral artery consistently shows up as the most frequently affected site in both living and post-mortem studies, though it rarely gets the same attention as the heart or neck arteries because it’s less likely to cause sudden, life-threatening events.
It Starts Much Younger Than You Think
Atherosclerosis is often thought of as a disease of old age, but autopsy studies paint a different picture. Fatty streaks, the earliest visible stage of atherosclerosis, appear in the aorta starting in the second decade of life. By the twenties and thirties, the process is well underway in many people. One autopsy study found coronary atherosclerosis in about 85% of people aged 21 to 30 and in 100% of those aged 31 to 40.
Those numbers come from a population-based autopsy series, meaning the people studied died from various causes, not just heart disease. When researchers repeated the same study design a decade later, they found a notable increase: in the 31 to 40 age group, the frequency of coronary atherosclerosis jumped from 75% to 100%. This suggests the disease is becoming more common in younger adults over time, likely reflecting changes in diet, activity levels, and obesity rates.
How Gender Affects Timing and Risk
Men develop atherosclerosis earlier. They generally have a higher plaque burden than women, and this gap is most obvious in younger age groups. Vascular aging kicks in sooner for men, and conditions like heart attacks tend to occur at younger ages.
Women, however, catch up. After menopause, cardiovascular risk rises sharply. The protective effect of estrogen fades, and the rate of arterial aging actually accelerates faster in women than in men during this period. A Dutch study of over 8,400 adults older than 55 found that the lifetime risk of developing cardiovascular disease in elderly women eventually equaled that of men. Among the oldest age groups, the prevalence of cardiovascular disease in women surpasses that of men.
The Global Death Toll
Atherosclerosis is the engine behind cardiovascular disease, which is the leading cause of death in the world. In 2022, an estimated 19.8 million people died from cardiovascular diseases, roughly 32% of all deaths globally. Of those, 85% were due to heart attacks and strokes, both of which are direct consequences of atherosclerotic plaque rupture or arterial blockage.
That burden is expected to grow. Aging populations worldwide, combined with rising rates of metabolic risk factors like obesity and diabetes, mean that atherosclerotic diseases will continue driving cardiovascular deaths upward in the coming decades. Ischemic heart disease and stroke remain the two largest contributors.
How Risk Factors Change the Odds
While atherosclerosis is common across the board, certain risk factors dramatically accelerate it. Smoking increases the risk of coronary heart disease and stroke by two to four times compared to not smoking. Even secondhand smoke raises heart disease risk by 25% to 30% and stroke risk by 20% to 30%.
Metabolic syndrome, a cluster of conditions including high blood pressure, high blood sugar, excess abdominal fat, and abnormal cholesterol, follows a different pattern in men and women. In men, it starts rising in the twenties and peaks between 50 and 60. In women, it continues climbing steadily with age and never really plateaus. Diabetes, high cholesterol, physical inactivity, and chronic inflammation all contribute to faster plaque buildup. The more risk factors present, the more widespread and severe the disease tends to be.
Why Most People Don’t Know They Have It
The defining feature of atherosclerosis is how long it stays hidden. Arteries can lose a significant portion of their internal diameter before blood flow is restricted enough to cause symptoms. Most people with early or moderate plaque buildup feel completely normal. The 23% prevalence figure from imaging studies of asymptomatic adults is a floor estimate, since ultrasound only detects plaque that has reached a certain size, and it only examines one or two arterial locations.
This silent progression is why atherosclerosis often announces itself with a major event: a heart attack, a stroke, or sudden leg pain from blocked circulation. By the time symptoms appear, the disease has typically been developing for decades. Coronary calcium scoring, a type of CT scan, and carotid ultrasound can detect subclinical disease years before it becomes dangerous, but these tests aren’t part of routine screening for most people. Standard risk factor management (controlling blood pressure, cholesterol, blood sugar, and weight, and not smoking) remains the primary strategy for slowing a process that, statistically speaking, is already underway in most adults.