Cholesterol
A waxy substance your body needs and your arteries would rather you not overdo.
By Greg Goodwin · Published October 24, 2026
Cheat Sheet
- Threshold: CDC defines high total cholesterol as 240 mg/dL or more.
- Prevalence: 10% of US adults age 20 and older had total cholesterol above 240 mg/dL in 2017 to 2020, nearly 25 million people.
- Borderline and up: about 86 million US adults age 20 and older have total cholesterol above 200 mg/dL.
- Low HDL: about 17% of adults had HDL ("good") cholesterol below 40 mg/dL.
- Children: about 7% of US children and adolescents ages 6 to 19 have high total cholesterol.
- Testing rhythm: most healthy adults should have cholesterol checked every 4 to 6 years, more often with heart disease, diabetes, or family history.
The 60-Second Version
Cholesterol is a waxy, fat-like substance found in every cell of the body. You need some of it to build cell membranes and make certain hormones, and your liver makes much of what you need. Trouble comes when levels in the blood run too high, especially of the type called LDL, because the excess can build up in artery walls as plaque, narrowing them and raising the risk of heart disease and stroke, two leading causes of death in the United States. High cholesterol has no symptoms, so the only way to know is a simple blood test. CDC defines high total cholesterol as 240 mg/dL or more. The picture also depends on HDL, LDL, and triglycerides together, and on a person's other risks. This page is general information, not medical advice; a clinician interprets results.
The Long Version
What Cholesterol Actually Does
Cholesterol is not a villain by design. The body uses it to build cell walls and to make hormones and substances that aid digestion. Because it does not dissolve in blood, it travels packaged with proteins as lipoproteins. LDL carries cholesterol out to the tissues and, in excess, contributes to deposits in artery walls. HDL is the type associated with carrying cholesterol back toward the liver, which is why it earns the nickname good cholesterol. A lipid panel typically reports total cholesterol, LDL, HDL, and triglycerides, a separate blood fat, and clinicians weigh them together rather than relying on any single number.
Why High Levels Matter
As the CDC puts it, too much cholesterol puts you at risk for heart disease and stroke. Over years, cholesterol and other material accumulate as plaque, narrowing arteries and sometimes triggering clots. CDC's stroke page lists high cholesterol alongside high blood pressure, smoking, obesity, and diabetes as leading causes of stroke, and notes one in three US adults has at least one of these conditions or risk factors. Because the process is slow and silent, many people feel perfectly fine while risk builds, which is the central reason testing is recommended even when nothing seems wrong.
The Numbers
CDC defines high total cholesterol as 240 mg/dL or more. In 2017 to 2020, 10% of US adults age 20 and older had total cholesterol above 240 mg/dL, nearly 25 million people, and about 86 million adults had levels above 200 mg/dL. Another 17% had HDL below 40 mg/dL. Among adults who could benefit from cholesterol medicine, slightly more than half, 54.5% or 47 million people, were taking it, according to CDC citing 2011 to 2016 data. Many secondary sources cite 200 mg/dL as the cutoff for high; CDC's own wording uses 240, and desirable ranges can differ by source and by individual risk.
Who Is Affected and Testing
Prevalence varies by group. Among adults in 2017 to 2020, high total cholesterol ranged from 6.9% of non-Hispanic Black men to 13.0% of non-Hispanic Asian men, and from 8.7% to 10.7% among women across the groups CDC lists. About 7% of US children and adolescents ages 6 to 19 have high total cholesterol. CDC says about two thirds of US adults report having had their cholesterol checked in the last 5 years, and that most healthy adults should be checked every 4 to 6 years, with more frequent checks for those with heart disease, diabetes, or a family history of high cholesterol.
Talking It Through With a Clinician
What a given cholesterol number means depends on age, family history, blood pressure, smoking, diabetes, and other factors, which is why interpretation is individual. Clinicians use test results together with these risks to discuss whether lifestyle changes, medication, or neither fits a patient. CDC provides general information on testing, prevention, and treatment but does not replace that conversation. A useful habit is simply knowing your numbers, asking what they mean for you, and not relying on internet cutoffs, which can be outdated or oversimplified.
Why People Care
High cholesterol is common, silent, and tied to heart disease and stroke, so a quick blood test can reveal something you cannot feel. Knowing the terms makes a lab report less intimidating. This is general information, not medical advice; ask a clinician what your results mean.
Glossary
- LDL cholesterol
- Low-density lipoprotein, often called "bad" cholesterol because high levels contribute to plaque buildup in arteries.
- HDL cholesterol
- High-density lipoprotein, often called "good" cholesterol; low levels are considered unfavorable.
- Triglycerides
- A type of fat in the blood that is measured along with cholesterol in a lipid panel.
- Lipid panel
- A blood test that reports total cholesterol, LDL, HDL, and triglycerides.
- Plaque
- A buildup of cholesterol and other material in artery walls that can narrow them.
Go Deeper
More to Explore
- Blood Pressure
Two numbers, one cuff, and the quietest early-warning system your body has.
- Pandemics
Pandemics have reshaped history, from medieval Europe to the modern world.
- Organ Transplants
The first successful organ transplant, in 1954, worked only because the donor and recipient were identical twins.
- Anesthesia
Anesthesia has worked safely for over a century, yet scientists still can't fully explain how it switches consciousness off.
- Vaccines
Vaccines helped wipe smallpox off the planet entirely, with no natural cases since the late 1970s.