What Is Cholesterol and Why Does It Matter?
Cholesterol is a waxy, fat-like substance your body needs to build cells and make hormones, but too much cholesterol in your blood forms plaque in arteries, restricting blood flow and dramatically increasing risk of heart attack and stroke.
Your body makes all the cholesterol it needs in the liver, but you also get cholesterol from animal-based foods like meat, eggs, and dairy. Cholesterol travels through your bloodstream in particles called lipoproteins. LDL (low-density lipoprotein) is often called 'bad' cholesterol because it deposits cholesterol in artery walls, forming plaque that narrows and stiffens arteries (atherosclerosis). HDL (high-density lipoprotein) is 'good' cholesterol because it picks up excess cholesterol and carries it back to the liver for disposal. Triglycerides are another type of blood fat that, when elevated, also increases cardiovascular risk.
High cholesterol is dangerous precisely because it has no symptoms—you can't feel it damaging your arteries. Over years or decades, plaque buildup narrows arteries throughout your body, reducing oxygen delivery to vital organs. When plaque ruptures, it triggers blood clots that can completely block arteries, causing heart attack or stroke. Nearly 94 million American adults age 20 or older have total cholesterol levels above 200 mg/dL, and 28 million have levels above 240 mg/dL. People with high cholesterol have roughly double the risk of heart disease compared to those with optimal levels.
What Are Healthy Cholesterol Levels?
Total cholesterol should be below 200 mg/dL, LDL below 100 mg/dL (or below 70 mg/dL for high-risk individuals), HDL above 60 mg/dL for protection, and triglycerides below 150 mg/dL. Your target levels depend on your overall cardiovascular risk.
The American Heart Association and American College of Cardiology provide these general guidelines: Total cholesterol below 200 mg/dL is desirable, 200-239 mg/dL is borderline high, and 240 mg/dL or higher is high. For LDL cholesterol, below 100 mg/dL is optimal for most people, though those with coronary artery disease or diabetes should aim for below 70 mg/dL. Near optimal is 100-129 mg/dL, borderline high is 130-159 mg/dL, high is 160-189 mg/dL, and very high is 190 mg/dL or above. For HDL, higher is better: below 40 mg/dL for men and below 50 mg/dL for women is a risk factor, while 60 mg/dL or higher is protective.
However, treatment decisions aren't based on cholesterol levels alone. Doctors now use cardiovascular risk calculators that consider age, sex, race, total and HDL cholesterol, blood pressure, diabetes status, and smoking to estimate your 10-year risk of heart attack or stroke. If your 10-year risk is 7.5% or higher, or if you have diabetes, existing cardiovascular disease, or LDL above 190 mg/dL, you'll likely need cholesterol-lowering medication regardless of specific numbers. This personalized approach treats cholesterol in the context of overall cardiovascular risk rather than treating numbers in isolation.
How Is High Cholesterol Diagnosed?
High cholesterol is diagnosed through a blood test called a lipid panel or lipid profile, which measures total cholesterol, LDL, HDL, and triglycerides. Most adults should be screened every 4-6 years, or more frequently if at high risk.
A complete lipid panel requires fasting for 9-12 hours beforehand, though newer guidelines allow non-fasting tests for initial screening. The test measures four values: total cholesterol, LDL cholesterol, HDL cholesterol, and triglycerides. Your doctor calculates additional values like non-HDL cholesterol (total minus HDL) and the cholesterol ratio (total divided by HDL). The American Heart Association recommends all adults age 20 or older have cholesterol checked every 4-6 years. More frequent testing is recommended if you have cardiovascular disease, diabetes, family history of high cholesterol or early heart disease, or are taking cholesterol-lowering medication.
Children and adolescents should also be screened, especially if there's family history of high cholesterol or premature heart disease. Initial screening is recommended between ages 9-11, with repeat screening at ages 17-21. Some children with familial hypercholesterolemia (inherited high cholesterol) have LDL levels above 190 mg/dL and may develop heart disease in their 20s or 30s without treatment. Early detection through family screening and genetic testing allows early intervention that can prevent premature cardiovascular disease.
What Lifestyle Changes Lower Cholesterol?
The most effective lifestyle interventions are reducing saturated fat to under 6% of calories, eliminating trans fats, eating 5-10 grams of soluble fiber daily, exercising 150 minutes weekly, losing 5-10% of body weight if overweight, and quitting smoking.
Dietary changes are fundamental to cholesterol management. Reduce saturated fats (found in red meat, full-fat dairy, butter, and tropical oils) to less than 6% of daily calories—for a 2,000-calorie diet, that's about 13 grams. Completely eliminate trans fats found in partially hydrogenated oils, many margarines, and commercial baked goods. Increase soluble fiber to 5-10 grams daily through oatmeal, oat bran, beans, lentils, apples, pears, and brussels sprouts—soluble fiber binds cholesterol in the intestines, preventing absorption. Add plant sterols (2 grams daily from fortified foods or supplements) which block cholesterol absorption. Eat fatty fish like salmon, mackerel, or sardines twice weekly for omega-3 fatty acids that lower triglycerides and reduce inflammation.
Regular physical activity raises HDL ('good') cholesterol and lowers triglycerides. Aim for at least 150 minutes of moderate aerobic exercise weekly (brisk walking, swimming, cycling) or 75 minutes of vigorous activity. Even modest weight loss of 5-10 pounds if overweight can improve cholesterol levels. Quitting smoking raises HDL by up to 10% within weeks and provides enormous cardiovascular benefits beyond cholesterol. Limiting alcohol to moderate amounts (up to one drink daily for women, two for men) may raise HDL slightly but can increase triglycerides. These lifestyle changes together can lower LDL cholesterol by 10-20% and significantly reduce cardiovascular risk even before considering medication.
What Medications Treat High Cholesterol?
Statins are first-line medications that reduce LDL cholesterol by 30-50% and significantly decrease heart attack and stroke risk. Other options include ezetimibe, PCSK9 inhibitors, bile acid sequestrants, and fibrates, often used in combination for optimal lipid control.
Statins (atorvastatin, rosuvastatin, simvastatin, pravastatin) work by blocking an enzyme your liver needs to make cholesterol, forcing the liver to pull LDL cholesterol from your blood. They're the most effective and well-studied cholesterol medications, reducing LDL by 30-50% depending on dose and specific statin. Large trials show statins reduce heart attacks by about 30% and strokes by about 20%. High-intensity statins (atorvastatin 40-80 mg, rosuvastatin 20-40 mg) lower LDL by 50% or more, while moderate-intensity statins lower LDL by 30-50%. Common side effects include muscle aches (5-10% of users), which often resolve by switching statins or reducing dose. Serious side effects like rhabdomyolysis or liver damage are rare (less than 1%).
When statins alone don't reach LDL goals, or if statin side effects limit use, other medications can help. Ezetimibe blocks cholesterol absorption in the intestines, lowering LDL by an additional 15-20% when added to statins. PCSK9 inhibitors (evolocumab, alirocumab) are injectable medications that lower LDL by 50-60% and are used in very high-risk patients or those with familial hypercholesterolemia. Bile acid sequestrants (cholestyramine, colesevelam) bind bile acids containing cholesterol, forcing the liver to use more cholesterol to make new bile. Fibrates (fenofibrate) primarily lower triglycerides but also modestly raise HDL. Bempedoic acid is a newer oral medication for people who can't tolerate statins. Omega-3 fatty acid prescriptions (icosapent ethyl) reduce triglycerides and cardiovascular events in high-risk patients.
Who Should Take Cholesterol Medication?
Cholesterol medication is recommended for people with existing cardiovascular disease, LDL above 190 mg/dL, diabetes (age 40-75), or 10-year cardiovascular risk of 7.5% or higher. Treatment decisions balance cholesterol levels, overall risk, and individual patient factors.
Current guidelines identify four groups who benefit from statin therapy: (1) Anyone with clinical atherosclerotic cardiovascular disease (prior heart attack, stroke, stable or unstable angina, coronary or other arterial revascularization). These individuals face highest risk and should take high-intensity statins to reduce LDL by at least 50%. (2) People with LDL cholesterol 190 mg/dL or higher, which often indicates familial hypercholesterolemia—they should start high-intensity statins regardless of other risk factors. (3) Adults age 40-75 with diabetes and LDL 70-189 mg/dL should take at least moderate-intensity statins. (4) Adults age 40-75 without diabetes but with LDL 70-189 mg/dL and 10-year cardiovascular risk of 7.5% or higher should discuss statin therapy with their doctor.
For people with 10-year risk between 5-7.5%, treatment decisions are individualized based on additional factors: family history of premature cardiovascular disease, chronic kidney disease, metabolic syndrome, preeclampsia history, premature menopause, inflammatory conditions like rheumatoid arthritis, or elevated lipoprotein(a). A coronary artery calcium score (a specialized CT scan) can help guide decisions in borderline cases—if the scan shows significant calcification, statins are more strongly recommended. The decision to start medication should be shared between you and your doctor, weighing your specific risk factors, preferences, and treatment goals rather than relying on cholesterol numbers alone.
