What Cholesterol Levels Mean and Why They Matter

If you or loved ones have high cholesterol, you probably already know it’s a cause for concern. The levels of cholesterol in your blood are linked to a risk for cardiovascular problems, including heart attacks and strokes. But even if your cholesterol levels are normal, you need to be mindful of what cholesterol is and what you can do to keep your numbers in a healthy range.

Thankfully, finding out your cholesterol level is a relatively painless process. And once you know those numbers, you can better adjust your lifestyle and medications to improve your health.

(Related: My Breast Lump Wasn’t Cancer—It Was a Sign of High Cholesterol)

What is cholesterol?

The American Heart Association (AHA) describes cholesterol as a waxy substance that circulates in your blood. It is a normal, healthy product of your liver. But too much cholesterol can lead to clogged arteries, and that puts you at risk for a heart attack and stroke. High cholesterol is a common concern in Canada. An estimated 28 percent of Canadians over the age of 18 have elevated levels, according to Statistics Canada.

Most adults have their cholesterol levels checked every four to six years. That might be enough if you are a young, healthy adult. But older adults or those at risk for cardiovascular disease should opt for a cholesterol test every other year.

What causes high cholesterol?

Though genetics can play a role, experts suggest that lifestyle factors have the most influence on cholesterol levels. The most common cause of unhealthy or high cholesterol are:

• Diet. Eating foods that are high in saturated fat and trans fat can cause your liver to make more cholesterol than normal. These fats are common in some animal products, as well as unhealthy fried and processed foods.
• Lack of exercise. A sedentary lifestyle leads to lower HDL (“good” cholesterol) levels.
• Smoking. Lighting up can lead to unhealthy cholesterol levels, but quitting can improve your numbers. In fact, one study found that stopping smoking improved HDL levels, even when people who quit gained weight.

Your gender can also affect blood cholesterol levels as you age. Research published in the journal Healthcare suggests that menopause influences women’s cholesterol levels. Premenopausal women generally have lower LDL and higher HDL levels than men, according to a study published in Circulation. That’s because estrogen improves cholesterol. During menopause, though, estrogen levels plummet.

(Related: Trans Fat vs. Saturated Fat: What’s the Difference?)

Health risks of high cholesterol

The longer you live with high cholesterol, the longer you remain exposed to these associated health risks, as outlined by the National Heart, Lung, and Blood Institute:

• Coronary heart disease (the risk most strongly associated with high cholesterol)
• Heart attack
• Stroke
• Peripheral arterial disease
• Carotid artery disease
• Sudden cardiac arrest

Getting your cholesterol checked regularly allows you to react quickly to unhealthy levels. Your cholesterol numbers are used with the American College of Cardiology’s formula for calculating your 10-year risk of having a heart attack or stroke.

When and how should cholesterol be tested?

Adults 20 years and older should get a cholesterol test at least once every five years. The American Academy of Pediatrics recommends children get their cholesterol levels checked once between ages 9 and 11 and again between 17 and 21. Anyone with a heightened risk of heart disease (like kids with type 2 diabetes, for instance) should get their cholesterol tested even more often. Cholesterol levels are measured through a blood sample. Most people get their cholesterol tested in the morning because the test requires several hours of fasting beforehand.

If you have your cholesterol tested at your doctor’s office, you will give a blood sample through a vein in your arm. Experts will measure the number of milligrams (mg) of cholesterol per deciliter (dl) in your blood sample.

At-home cholesterol kits and lipid panels (a measurement of cholesterol and other blood fats) can also give you an accurate reading. But look for kits that are FDA approved and state they’re traceable to a CDC program. You will need to prick your finger and then carefully follow instructions for blood collection and test strip application. At-home kits offer helpful estimations, but they should not take the place of your quinquennial cholesterol screening.

(Related: 6 Types of Heart Disease Doctors Need You to Know)

What cholesterol tests measure

A cholesterol screening will yield at least three measurements:

• Total cholesterol
• LDL cholesterol
• HDL cholesterol

Below, learn what these measurements mean and which goals to aim for.

Total cholesterol

This measures all of the cholesterol in your blood, including LDL, HDL, and triglycerides.

LDL cholesterol

Low-density lipoproteins (LDL) are a mix of fat (lipid) and protein—hence the term lipoprotein. LDL is considered “bad” cholesterol for a reason: it can clog your arteries, which ups your chances of having a heart attack or stroke.

HDL cholesterol

High-density lipoproteins (HDL) soak up excess cholesterol from your blood vessels and shuttles it back to your liver for disposal. That’s why it is often called “good” cholesterol. High HDL levels might lower your risk of LDL-related heart disease.

Triglycerides

Sometimes a lipid panel will include a measure of your triglycerides, a type of fat. Like high cholesterol, high triglycerides can increase your risk of heart disease.

Other lipid panel components

Your test results might also include additional measurements:

• Non-HDL cholesterol: The number reflects your total cholesterol minus HDL.
• Very-low-density lipoprotein (VLDL): It’s similar to LDL cholesterol, but while low-density lipoproteins mostly carry cholesterol to your tissues, very-low-density lipoproteins transport triglycerides.

Put together, all these test measures give your doctor a detailed glimpse of your blood’s lipid content and thus your risk of restricted blood flow and heart disease.

(Related: 6 Things You Probably Don’t Know About Heart Health)

Cholesterol levels in men

Younger men tend to have higher total cholesterol numbers than women. This changes after women go through menopause, which tends to raise women’s cholesterol levels. In general, men and women have very similar target cholesterol levels. The one difference: men have a slightly lower HDL target of 40 mg/dl.

Cholesterol levels in women

As noted, women with healthy cholesterol levels have slightly higher HDL counts than men. That’s because estrogen increases HDL cholesterol and lowers LDL cholesterol, as noted in the Circulation study.

Because of estrogen’s protective effects, women tend to have a lower risk of heart disease before the age of 65. Once women have gone through menopause, their risk of heart attack and stroke is equal to men’s risk.

While men and women have similar targets numbers for total cholesterol, LDL, and triglycerides, women need to aim a little higher when it comes to HDL. The goal is 50 mg/dl or higher.

Cholesterol levels in children

Seven percent of American children between the ages of 6 and 19 have high cholesterol, according to the CDC. That’s compared with 12 percent of American adults who have high levels.

Though children are less likely than adults to have unhealthy cholesterol levels, they should be tested nonetheless. Any child or adult with a family history of high cholesterol, heart disease, or diabetes should be particularly vigilant about having their cholesterol checked.

Understanding your cholesterol test results

Healthy cholesterol levels vary slightly by age and gender. These are normal, borderline, and high cholesterol measurements according to the U.S. National Library of Medicine and Stanford Children’s Health.

Normal cholesterol levels

The recommended cholesterol levels for total, LDL, HDL, and non-HDL fall into these ranges.

Normal cholesterol levels for adults:

• Total: 125 to 200 mg/dl
• LDL: less than 100 mg/dl
• HDL: at least 50 mg/dl for women; at least 40 mg/dl for men
• Non-HDL: less than 130 mg/dl

Normal cholesterol levels for children:

• Total: less than 170 mg/dl
• LDL: less than 110 mg/dl
• HDL: at least 45 mg/dl
• Non-HDL: less than 120 mg/dl

Borderline cholesterol levels

If you have borderline high cholesterol, your levels are heightened but not significantly enough to be called “high.” Borderline cholesterol levels tell you that it’s time to make healthy lifestyle changes.

Borderline cholesterol levels for adults:

• Total: 200 to 239 mg/dl
• LDL: 130 to 159 mg/dl

Borderline cholesterol levels for children:

• Total: 170 to 199 mg/dl
• LDL: 110 to 129 mg/dl
• Non-HDL: 120 to 144 mg/dl

High cholesterol levels

High cholesterol raises your risk of heart disease, high blood pressure, and more. These ranges are considered high.

High cholesterol levels for adults:

• Total: 239 mg/dl and higher
• LDL: 160 mg/dl and higher
• Non-HDL: 130 mg/dl

High cholesterol levels for children:

• Total: 200 mg/dl and higher
• LDL: 130 mg/dl and higher
• Non-HDL: higher than 145 mg/dl

(Related: 16 Things Doctors Do to Lower Their High Cholesterol)

Can good cholesterol levels be too high or bad be too low?

In most cases, high HDL is not harmful. HDL is healthy, essential cholesterol. It helps keep your LDL levels in check. Some older research published in the medical journal Arteriosclerosis, Thrombosis, and Vascular Biology suggested that high HDL might increase the risk of heart disease in people who have high levels of C-reactive proteins, a sign of inflammation. More research is needed to confirm this finding. If you have abnormally high HDL and C-reactive protein levels, ask your doctor about your risk of heart disease.

As for too-low LDL levels, research is still ongoing. Early studies suggested very low levels of LDL cholesterol may be problematic. But other studies have found levels below 50 mg/dl safe, such as one published in 2018 in Current Pharmaceutical Design.

What is a cholesterol ratio?

You can find your cholesterol ratio by dividing your total cholesterol number by your HDL level. For instance, someone with a total cholesterol count of 200 mg/dl and HDL of 50 mg/dl has a 4-to-1 cholesterol ratio. Your cholesterol ratio is simply one more way to analyze the results of your cholesterol test. A lower ratio tends to signify better health because it reflects low total cholesterol and/or high HDL. In some situations, your doctor might use your cholesterol ratio to help determine your risk of heart disease. Cholesterol is just one important indicator of your overall health.

(Related: 9 Foods That’ll Lower Your Cholesterol Naturally)

What to do if your cholesterol is out of range

In some cases, high cholesterol can be managed with a combination of a healthy diet, regular exercise, and other lifestyle changes. Your doctor might also prescribe medication to treat high LDL levels.

Dietary changes

Your body makes all the cholesterol it needs, so it’s best to avoid high-cholesterol foods.

Try not to eat foods that are high in saturated fat or trans fat. This includes fatty animal products, like those hamburgers you love so much, your breakfast side of bacon, and full-fat milk and cheese. Tropical oils (like coconut) and many processed foods also make the list.

Lower your cholesterol by opting for foods low in saturated fat, trans fat, sugar, and salt. Smart options include whole grains, vegetables, fruits, and lean meats. High-fiber foods—think oatmeal, chia seeds, and beans—can also help you combat high LDL.

Other lifestyle changes

If you have high cholesterol, a combination of lifestyle tweaks could help you get your levels under control. These might include:

• Losing unhealthy weight
• Exercising regularly
• Quitting smoking
• Limiting alcohol to two daily drinks for men and one for women

Cholesterol-lowering medications

These work best when you also make the lifestyle changes necessary for healthy cholesterol levels. They include statins (the first-line treatment), bile acid sequestrants, niacin, fibrates, and PCSK9-inhibiting injections. Cholesterol-lowering medications should always be taken at the direction of a doctor. Side effects vary, so discuss your options carefully with your medical team.

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