High cholesterol means you have too much of a waxy, fat-like substance circulating in your blood. A total cholesterol level of 240 mg/dL or higher is classified as high, while 200 to 239 mg/dL falls in the borderline range. On its own, high cholesterol doesn’t cause symptoms you can feel, which is why many people don’t know they have it until a routine blood test reveals the numbers.
What Cholesterol Actually Does
Your body needs cholesterol. It’s a building block for cell membranes, hormones, and vitamin D. Your liver produces most of the cholesterol in your blood, and the rest comes from food. The problem isn’t cholesterol itself. It’s having too much of the wrong kind in circulation for too long.
Cholesterol travels through your bloodstream packaged inside proteins called lipoproteins. The three main types matter for different reasons:
- LDL (low-density lipoprotein) carries cholesterol from the liver to your tissues. When there’s too much, it deposits cholesterol in artery walls. This is why it’s called “bad” cholesterol. An optimal LDL level is below 100 mg/dL. Anything from 160 to 189 is considered high, and 190 or above is very high.
- HDL (high-density lipoprotein) works in reverse, picking up excess cholesterol and ferrying it back to the liver for disposal. Higher is generally better here: 60 mg/dL or above is ideal, while levels below 40 mg/dL in men or 50 mg/dL in women are considered low and increase risk.
- VLDL (very low-density lipoprotein) mainly carries triglycerides, another type of blood fat. Elevated VLDL contributes to plaque buildup in a similar way to LDL.
How High Cholesterol Damages Arteries
The real danger of high cholesterol plays out over years, inside your artery walls. When LDL levels stay elevated, the excess particles begin infiltrating the inner lining of blood vessels, particularly at spots where blood flow is turbulent, like artery branches. Once inside the vessel wall, LDL particles become chemically modified and trigger an immune response.
White blood cells rush to the area, swallow the modified cholesterol, and transform into bloated “foam cells.” These foam cells pile up and form fatty streaks, the earliest visible sign of atherosclerosis. Over time, more cholesterol, calcium, and cellular debris accumulate, building a thickened plaque that narrows the artery. If a plaque ruptures, it can trigger a blood clot that blocks blood flow entirely, causing a heart attack or stroke. This process can begin decades before any symptoms appear.
What Causes Cholesterol to Rise
Diet plays a role, but it’s not the whole story. Saturated fat (found in red meat, full-fat dairy, and fried foods) raises LDL levels more than dietary cholesterol itself does. Trans fats, still present in some processed foods, both raise LDL and lower HDL. Carrying excess weight, particularly around the midsection, tends to increase LDL and triglycerides while lowering HDL. Physical inactivity compounds the effect.
Age matters too. Cholesterol levels naturally rise as you get older, partly because the liver becomes less efficient at clearing LDL from the blood. Women often see a noticeable jump after menopause. Conditions like diabetes, hypothyroidism, and kidney disease can all push cholesterol higher independently of diet or exercise.
The Genetic Factor
Some people inherit genes that make their bodies overproduce LDL or fail to clear it efficiently. The most well-known form is familial hypercholesterolemia, caused by mutations in genes that control how LDL is removed from the bloodstream. The most common culprit is a mutation in the LDLR gene, which provides instructions for the receptor that pulls LDL out of circulation.
People with this condition can have LDL levels of 190 mg/dL or higher starting in childhood, even with a healthy diet. Physical signs sometimes develop: cholesterol deposits in the tendons (especially the Achilles tendon and hand tendons), yellowish patches under the skin of the eyelids, and a gray ring around the edge of the cornea. If one parent carries the mutation, you have a 50% chance of inheriting it. People with familial hypercholesterolemia face a significantly elevated risk of early heart disease and typically need medication from a young age.
How Cholesterol Is Tested
A simple blood draw called a lipid panel measures your total cholesterol, LDL, HDL, and triglycerides. You may not need to fast beforehand. Current guidelines from the American College of Cardiology and American Heart Association don’t require fasting for routine cardiovascular risk screening, and a joint consensus statement recommends non-fasting tests for most patients to improve compliance. Fasting (typically 9 to 12 hours) is still recommended in certain situations: before starting cholesterol-lowering medication, when triglycerides are very high (above 400 mg/dL), or when a precise diagnosis of a lipid disorder is needed.
Your doctor won’t look at cholesterol numbers in isolation. The standard risk assessment tool used in the U.S. combines your total cholesterol and HDL with your age, sex, race, blood pressure, whether you take blood pressure medication, diabetes status, and smoking status to estimate your 10-year risk of a cardiovascular event. Two people with the same LDL level can have very different risk profiles based on these other factors, which is why treatment decisions are personalized.
Cholesterol Targets at a Glance
- Total cholesterol: Below 200 mg/dL is desirable. 200 to 239 is borderline. 240 and above is high.
- LDL cholesterol: Below 100 mg/dL is optimal. 130 to 159 is borderline high. 160 to 189 is high. 190 and above is very high.
- HDL cholesterol: 60 mg/dL or above is protective. Below 40 (men) or 50 (women) increases cardiovascular risk.
Lifestyle Changes That Lower LDL
For many people, especially those with borderline or moderately high cholesterol, lifestyle changes are the first line of defense. Reducing saturated fat intake to less than 6% of daily calories typically produces a measurable drop in LDL within weeks. Replacing saturated fats with unsaturated fats (olive oil, nuts, avocados, fatty fish) helps shift the balance further.
Soluble fiber deserves special attention. Found in oats, beans, lentils, apples, and flaxseed, soluble fiber binds to cholesterol in the gut and carries it out of the body before it’s absorbed. Getting 5 to 10 grams or more of soluble fiber a day produces a meaningful decrease in LDL. For reference, a bowl of oatmeal has about 2 grams, and a cup of cooked black beans has around 5 grams, so hitting the target is achievable with modest dietary shifts.
Regular aerobic exercise (brisk walking, cycling, swimming) raises HDL and modestly lowers LDL and triglycerides. Losing even 5 to 10% of your body weight, if you’re carrying extra, can improve all three numbers. Quitting smoking raises HDL and improves blood vessel function within weeks.
When Medication Is Needed
If your cardiovascular risk is high enough, or if lifestyle changes aren’t bringing LDL down far enough, medication enters the picture. Statins are the most widely prescribed cholesterol drugs. They work by blocking an enzyme the liver needs to produce cholesterol. When the liver can’t make as much, it pulls more LDL out of the bloodstream to compensate, which lowers your circulating levels.
Moderate-intensity statin therapy lowers LDL by 30 to 50%. High-intensity statin therapy lowers it by more than 50%. Your doctor chooses the intensity based on your overall risk profile, not just your cholesterol numbers. Common side effects include muscle aches and, less frequently, digestive issues. Most people tolerate statins well, and for those who don’t, switching to a different statin or adjusting the dose often resolves the problem.
For people who can’t tolerate statins or need additional LDL lowering, other medication classes are available. Some block cholesterol absorption in the gut. Others, given as injections every two to four weeks, dramatically lower LDL by helping the liver clear it from the blood more effectively. These are typically reserved for people with very high LDL, familial hypercholesterolemia, or established cardiovascular disease who haven’t reached their target on statins alone.