Nearly 25 million adults in the United States have total cholesterol levels above 240 mg/dL, the threshold considered high. That works out to roughly 10% of all adults aged 20 and older, based on CDC data from 2017 to 2020. But the full picture is more nuanced than a single number, because millions more fall into borderline territory and a significant portion of people with elevated cholesterol don’t even know it.
What Counts as High Cholesterol
For adults 20 and older, a total cholesterol level below 200 mg/dL is considered healthy. Once it climbs above 240 mg/dL, it’s classified as high. The range between 200 and 239 mg/dL is borderline, which means a much larger share of Americans have cholesterol levels that aren’t ideal, even if they don’t meet the strict “high” cutoff.
Total cholesterol is only part of the picture. LDL cholesterol (often called “bad” cholesterol) should stay below 100 mg/dL for adults. HDL cholesterol (the protective kind) ideally sits at 60 mg/dL or above. For men, anything below 40 mg/dL is considered low, while for women the floor is 50 mg/dL. A person can have “normal” total cholesterol but still be at risk if their LDL is too high or their HDL is too low.
Who Is Most Affected
High cholesterol doesn’t hit every age group equally. Adults between 40 and 59 have the highest prevalence at 15.7%, compared to 7.5% among those aged 20 to 39. Interestingly, the rate dips slightly after 60, dropping to 11.4%. That dip likely reflects the widespread use of cholesterol-lowering medications among older adults rather than any natural improvement.
Men and women are affected at similar rates: 10.5% and 12.1%, respectively, a difference that isn’t statistically significant. Across racial and ethnic groups, the CDC has also found no meaningful differences in prevalence, meaning high cholesterol is broadly distributed across the U.S. population rather than concentrated in specific communities.
Many People Don’t Know Their Levels
One of the more striking findings is how many Americans are walking around with elevated LDL cholesterol and have never been told. Among people with LDL levels of 160 mg/dL or higher, roughly 4 in 10 are both unaware and untreated. For the youngest adults (ages 18 to 29), the number is far worse: 83.1% with high LDL don’t know about it, compared to 31.6% of adults 70 and older.
Several factors make someone more likely to be undiagnosed. Men are less likely to be aware than women (52.9% unaware versus 43.2%). Hispanic individuals have the highest rates of being unaware and untreated at 61.6%, compared to 49.2% for Black individuals and 44.3% for White individuals. People without health insurance are unaware at nearly twice the rate of those who are insured (63.8% versus 42.2%), suggesting that access to routine blood work plays a major role in detection.
Children and Teens Are Affected Too
High cholesterol isn’t only an adult problem. CDC data from 2021 to 2023 found that 16.5% of U.S. children and adolescents had at least one abnormal cholesterol measure. About 6.6% had high total cholesterol (200 mg/dL or above, using the same adult threshold), 6.7% had high non-HDL cholesterol, and 9.2% had low HDL cholesterol. For children 19 and under, a healthy total cholesterol is below 170 mg/dL, a stricter standard than for adults.
The Numbers Have Actually Improved
Despite how large these numbers are, the trend over the past two decades is heading in the right direction. The average total cholesterol for U.S. adults dropped from 206 mg/dL in 2005–2006 to 191 mg/dL in 2013–2014, then fell further to 187 mg/dL by 2015–2016. That’s a decline of nearly 20 points in about a decade.
Among adults taking cholesterol-lowering medications, average LDL cholesterol fell from 122 mg/dL in 2005–2006 to 101 mg/dL by 2015–2016. Greater use of statins and updated treatment guidelines have both contributed to the decline. Still, the improvements haven’t been evenly distributed, and the gap between who qualifies for treatment and who actually receives it remains significant.
Why It Matters Beyond the Numbers
High cholesterol has no symptoms on its own, which is exactly why so many cases go undetected. Over time, excess LDL cholesterol builds up in artery walls, narrowing them and raising the risk of heart attacks and strokes. A 2025 analysis from Johns Hopkins estimated that if every eligible American received cholesterol-lowering treatment in line with current guidelines, the risk of major cardiovascular events could drop by up to 27%. In practical terms, that would prevent tens of thousands of heart attacks and strokes each year.
Cholesterol screening is a simple blood draw, typically part of a routine checkup. Most adults should have their levels checked at least every four to six years, though people with risk factors like diabetes, obesity, or a family history of heart disease often need more frequent testing. Children are generally screened once between ages 9 and 11 and again between 17 and 21.