What Is High Cholesterol? Symptoms, Causes, and Treatments

What is high cholesterol?

Cholesterol is a waxy substance that circulates in your blood stream. You need a small amount of cholesterol to keep your cells healthy. But high cholesterol — especially the wrong kind — can cause health problems.

There are two types of cholesterol:

• LDL (low-density lipoprotein) cholesterol: This is often called “bad” cholesterol. Too much LDL raises your risk for heart attack and stroke. 

• HDL (high-density lipoprotein) cholesterol: This is known as “good” cholesterol. HDL can help remove excess cholesterol from the blood. 

High HDL may protect you against heart attack and stroke. However, HDL is complicated. And a high number doesn’t always mean that you’re protected. We used to think that a high HDL “cancelled out” a high LDL. Now we know that isn’t the case.

LDL is the cholesterol number we usually worry about. That’s because too much LDL cholesterol in the blood can cause buildup in the walls of your arteries. This is known as atherosclerosis or plaque. Cholesterol plaque puts you at risk for serious problems like heart attack, stroke, and even dementia.

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What are symptoms of high cholesterol?

High cholesterol doesn’t usually cause symptoms, but there are a few exceptions. When your cholesterol is extremely high, the following signs and symptoms can happen:

• Xanthomas are small yellow nodules that can appear on the knees, elbows, and other joints and tendons.

• Xanthelasmas are small yellow bumps near the inner corner of your eyes.

• Corneal arcus is a thin white line around the iris of your eye. 

Most of the time, these conditions don’t cause pain or interfere with normal function.

These signs are unusual. So, if you don’t have them, your cholesterol levels could still be high. For most people with high cholesterol, symptoms begin when an artery is blocked by cholesterol plaque. That’s when angina (heart pain), heart attack, or stroke happens.

What causes high cholesterol?

There are many different causes and risk factors that contribute to high cholesterol. Some of these are things you can control, while others are things you can’t. You may be more likely to have high cholesterol if you:

• Eat a diet high in saturated fat and/or cholesterol

• Have increased body fat or obesity

• Smoke tobacco

• Don’t exercise

• Have diabetes

• Live with liver or kidney disease

• Have an underactive thyroid (hypothyroid)

• Are over the age of 50

• Have gone through menopause

• Take certain medications

Even with a nutritious diet and lifestyle, you may have high cholesterol because of your family history. This is called familial hypercholesterolemia.

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How is high cholesterol diagnosed?

Cholesterol is measured with a blood test. The CDC recommends screening for high cholesterol at the following ages and intervals:

• A first test as early as age 9

• A second test between the ages of 17 and 21

• Every 4 to 6 years after the second test

• Every 1 to 2 years for men in their 40s and up and women in their 50s

• Yearly testing after age 65

If you have risk factors, or if your numbers are high, more frequent testing is usually needed. Screening tests are usually ordered by your primary healthcare professional.

In general, an LDL over 160 is considered high, even if you have no other risk factors. About 11% of people in the U.S. fall into this category. 

If your LDL number isn't technically in the “high” range, it may still be higher than the recommended range. Your ideal LDL number depends on your other health conditions, such as: 

• If you have no other health problems, then your LDL goal should be under 100.

• If you have heart disease, stroke, peripheral arterial disease, or diabetes, your ideal LDL is below 70.

• For some especially high risk individuals, research suggests that an LDL under 55 may become the new goal.

After your blood test, your primary healthcare professional will review your cholesterol levels with you to determine the next best steps.

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Lowering cholesterol through lifestyle

Small changes in your daily lifestyle can make a big difference in your cholesterol levels. You can improve your cholesterol by:

• Optimizing your nutrition by limiting unhealthy fats, cholesterol, and sugars

• Increasing the fiber in your diet

• Getting at least 150 minutes (2.5 hours) per week of aerobic exercise

• Asking your healthcare team for help if you smoke or use other forms of tobacco

• Limiting alcohol

Sometimes, these changes may be enough to get your LDL number down. But for some people, genetics or other medical conditions will keep your numbers high.

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Medications for high cholesterol

If your LDL cholesterol is too high, there are medications that can safely bring it down. People between ages 40 and 75 are most likely to need cholesterol medication.

Here are the types of medications most commonly used to help manage cholesterol. Some of these can be combined, when needed: 

• Statins are first-choice medications for treating high cholesterol. Examples of statins include atorvastatin (Lipitor), fluvastatin (Lescol), rosuvastatin calcium (Crestor), and simvastatin (Zocor).

• Selective cholesterol absorption inhibitors are fairly weak on their own. So they work best when combined with a statin or other cholesterol medication. Ezetimibe (Zetia) is the only available drug in this class. 

• PCSK9 inhibitors are injected under the skin. Examples include alirocumab (Praluent) and evolocumab (Repatha). They’re often combined with a statin. But they may be used on their own for people who can’t take statins.

• Adenosine triphosphate-citrate lyase inhibitors are another good choice for people who can’t take statins. Bempedoic acid (Nexletol) is the only available drug in this class. A combination pill with ezetimibe is available (Nexlizet).

• Bile acid sequestrants (resins) are the oldest and safest cholesterol medications. However, they aren’t as effective as other drugs for preventing heart attacks or stroke. Examples include cholestyramine (Questran, Prevalite, LoCholest) and colestipol (Colestid).

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