Understanding High Cholesterol

Overview

Cholesterol is a waxy substance that's found in the fats (lipids) in your blood. While your body needs cholesterol to continue building healthy cells, having high cholesterol can increase your risk for heart disease.

When you have high cholesterol, you may develop fatty deposits in your blood vessels. Eventually, these deposits make it difficult for enough blood to flow through your arteries. Your heart may not get as much oxygen-rich blood as it needs, which increases the risk of a heart attack. Decreased blood flow to your brain can cause a stroke.

High cholesterol can be inherited, but it's often the result of unhealthy lifestyle choices, and thus preventable and treatable. A healthy diet, regular exercise, and sometimes medication can go a long way toward reducing high cholesterol.

Symptoms

High cholesterol has no symptoms. A blood test is the only way to detect high cholesterol.

When to see a doctor

Ask your doctor if you should have a cholesterol test. Recommendations for the age of first screening vary. Retesting is usually performed every five years.

If your test results aren't within desirable ranges, your doctor may recommend more frequent measurements. Your doctor may also suggest you have more frequent tests if you have a family history of high cholesterol, heart disease, or other risk factors, such as smoking, diabetes, or high blood pressure.

Causes

Cholesterol is carried through your blood, attached to proteins. This combination of proteins and cholesterol is called a lipoprotein. You may have heard of different types of cholesterol, based on what type of cholesterol the lipoprotein carries. They are:

• Low-density lipoprotein (LDL). LDL, or "bad," cholesterol transports cholesterol particles throughout your body. LDL cholesterol builds up in the walls of your arteries, making them hard and narrow.

• High-density lipoprotein (HDL). HDL, or "good," cholesterol picks up excess cholesterol and takes it back to your liver.

Factors within your control—such as inactivity, obesity, and an unhealthy diet—contribute to high LDL cholesterol and low HDL cholesterol. Factors beyond your control may play a role, too. For example, your genetic makeup may keep cells from removing LDL cholesterol from your blood efficiently or cause your liver to produce too much cholesterol.

Risk factors

Factors that may increase your risk of high cholesterol include:

• Poor diet. Eating saturated fat, found in animal products, and trans fats, found in some commercially baked cookies and crackers, can raise your cholesterol level. Foods that are high in cholesterol, such as red meat and full-fat dairy products, will also increase your total cholesterol.

• Obesity. Having a body mass index (BMI) of 30 or greater puts you at risk of high cholesterol.

• Large waist circumference. Your risk increases if you are a man with a waist circumference of at least 40 inches (102 centimeters) or a woman with a waist circumference of at least 35 inches (89 centimeters).

• Lack of exercise. Exercise helps boost your body's HDL, or "good," cholesterol while increasing the size of the particles that make up your LDL, or "bad," cholesterol, which makes it less harmful.

• Smoking. Cigarette smoking damages the walls of your blood vessels, making them likely to accumulate fatty deposits. Smoking may also lower your level of HDL, or "good," cholesterol.

• Diabetes. High blood sugar contributes to higher LDL cholesterol and lower HDL cholesterol. High blood sugar also damages the lining of your arteries.

Complications

High cholesterol can cause atherosclerosis, a dangerous accumulation of cholesterol and other deposits on the walls of your arteries. These deposits (plaques) can reduce blood flow through your arteries, which can cause complications, such as:

• Chest pain. If the arteries that supply your heart with blood (coronary arteries) are affected, you may have chest pain (angina) and other symptoms of coronary artery disease.

• Heart attack. If plaques tear or rupture, a blood clot may form at the plaque-rupture site—blocking the flow of blood or breaking free and plugging an artery downstream. If blood flow to part of your heart stops, you'll have a heart attack.

• Stroke. Similar to a heart attack, if blood flow to part of your brain is blocked by a blood clot, a stroke occurs.

Diagnosis

A blood test to check cholesterol levels—called a lipid panel or lipid profile—typically reports:

• Total cholesterol

• LDL cholesterol

• HDL cholesterol

• Triglycerides—a type of fat in the blood

For the most accurate measurements, don't eat or drink anything (other than water) for nine to 12 hours before the blood sample is taken.

Interpreting the numbers

In the United States, cholesterol levels are measured in milligrams (mg) of cholesterol per deciliter (dL) of blood. In Canada and many European countries, cholesterol levels are measured in millimoles per liter (mmol/L). To interpret your test results, use these general guidelines.

Total cholesterol

LDL cholesterol

HDL cholesterol

Triglycerides

Canadian and European guidelines differ slightly from U.S. guidelines. These conversions are based on U.S. guidelines.

Children and cholesterol testing

For most children, the National Heart, Lung, and Blood Institute recommends one cholesterol screening test between the ages of 9 and 11, and another cholesterol screening test between the ages of 17 and 21.

Cholesterol testing is usually avoided between the ages of 12 and 16 because false-negative results are more likely within this age group.

If your child has a family history of early-onset heart disease or a personal history of obesity or diabetes, your doctor may recommend earlier or more frequent cholesterol testing.

Treatment

Lifestyle changes such as exercising and eating a healthy diet are the first line of defense against high cholesterol. But, if you've made these important lifestyle changes and your cholesterol levels remain high, your doctor may recommend medication.

The specific choice of medication or combination of medications depends on various factors, including your individual risk factors, your age, your current health, and possible side effects. Common choices include:

• Statins. Statins block a substance your liver needs to make cholesterol. This causes your liver to remove cholesterol from your blood. Statins may also help your body reabsorb cholesterol from built-up deposits on your artery walls, potentially reversing coronary artery disease. Choices include atorvastatin (Lipitor), fluvastatin (Lescol), lovastatin (Altoprev), pitavastatin (Livalo), pravastatin (Pravachol), rosuvastatin (Crestor), and simvastatin (Zocor).

• Bile-acid-binding resins. Your liver uses cholesterol to make bile acids, a substance needed for digestion. The medications cholestyramine (Prevalite), colesevelam (Welchol), and colestipol (Colestid) lower cholesterol indirectly by binding to bile acids. This prompts your liver to use excess cholesterol to make more bile acids, which reduces the level of cholesterol in your blood.

• Cholesterol absorption inhibitors. Your small intestine absorbs the cholesterol from your diet and releases it into your bloodstream. The drug ezetimibe (Zetia) helps reduce blood cholesterol by limiting the absorption of dietary cholesterol. Ezetimibe can be used in combination with a statin drug.

• Injectable medications. A new class of drugs can help the liver absorb more LDL cholesterol—which lowers the amount of cholesterol circulating in your blood. Alirocumab (Praluent) and evolocumab (Repatha) may be used for people who have a genetic condition that causes very high levels of LDL or in people with a history of coronary disease who have intolerance to statins or other cholesterol medications.

Medications for high triglycerides

If you also have high triglycerides, your doctor may prescribe:

• Fibrates. The medications fenofibrate (TriCor, Fenoglide, others) and gemfibrozil (Lopid) decrease triglycerides by reducing your liver's production of very-low-density lipoprotein (VLDL) cholesterol and by speeding up the removal of triglycerides from your blood. VLDL cholesterol contains mostly triglycerides.

• Niacin. Niacin decreases triglycerides by limiting your liver's ability to produce LDL and VLDL cholesterol. But niacin doesn't provide any additional benefit than using statins alone. Niacin has also been linked to liver damage and stroke, so most doctors now recommend it only for people who can't take statins.

• Omega-3 fatty acid supplements. Omega-3 fatty acid supplements can help lower your triglycerides. They are available by prescription or over-the-counter. If you choose to take over-the-counter supplements, get your doctor's OK first. Omega-3 fatty acid supplements could affect other medications you're taking.

Tolerance varies.

Tolerance of medications varies from person to person. The common side effects are muscle pains, stomach pain, constipation, nausea, and diarrhea. If you decide to take cholesterol medication, your doctor may recommend liver function tests to monitor the medication's effect on your liver.

Children and cholesterol treatment

Diet and exercise are the best initial treatment for children age 2 and older who have high cholesterol or who are obese. Children age 10 and older might be prescribed cholesterol-lowering drugs, such as statins, if they have extremely high cholesterol levels.

Alternative medicine

Few natural products have been proven to reduce cholesterol, but some might be helpful. With your doctor's OK, consider these cholesterol-lowering supplements and products:

• Barley

• Beta-sitosterol (found in oral supplements and some margarines, such as Promise Activ)

• Blond psyllium (found in seed husk and products such as Metamucil)

• Oat bran (found in oatmeal and whole oats)

• Sitostanol (found in oral supplements and some margarines, such as Benecol)

Some red yeast rice products contain monacolin K, which is chemically identical to the prescription drug lovastatin. The FDA has prohibited the sale of these products, since there's no way to determine the quantity or quality of the active ingredient.

If you choose to take cholesterol-lowering supplements, remember the importance of a healthy lifestyle. If your doctor prescribes medication to reduce your cholesterol, take it as directed. Make sure your doctor knows which supplements you're taking as well.

Preparing for an appointment

If you think you may have high cholesterol, or are worried about having high cholesterol because of a strong family history, make an appointment with your family doctor to have your cholesterol level checked.

Because appointments can be brief, and because there's often a lot of ground to cover, it's a good idea to be prepared for your appointment. Here's some information to help you get ready for your appointment, and what to expect from your doctor.

What you can do

• Be aware of any pre-appointment restrictions. At the time you make the appointment, be sure to ask if there's anything you need to do in advance, such as restrict your diet. For a cholesterol test, you will likely have to avoid eating or drinking anything (other than water) for nine to 12 hours before the blood sample is taken.

• Write down any symptoms you're experiencing. High cholesterol itself has no symptoms, but high cholesterol is a risk factor for heart disease. Letting your doctor know if you have symptoms such as chest pains or shortness of breath can help your doctor decide how aggressively your high cholesterol needs to be treated.

• Write down key personal information, including a family history of high cholesterol, heart disease, stroke, high blood pressure, or diabetes, and any major stresses or recent life changes, as well as exposure to other cardiac risks, such as a personal history of smoking or exposure to family members who smoke (secondary exposure).

• Make a list of all medications, as well as any vitamins or supplements, that you're taking.

• Take a family member or friend along, if possible. Sometimes it can be difficult to soak up all the information provided to you during an appointment. Someone who accompanies you may remember something that you missed or forgot.

• Be prepared to discuss your diet and exercise habits. If you don't already exercise or eat a healthy diet, be ready to talk to your doctor about any challenges you might face in getting started.

• Write down questions to ask your doctor.

Your time with your doctor is limited, so preparing a list of questions will help you make the most of your time together. List your questions from most important to least important in case time runs out. For high cholesterol, some basic questions to ask your doctor include:

• What kinds of tests will I need?

• What's the best treatment?

• What foods should I eat or avoid?

• What's an appropriate level of physical activity?

• How often do I need a cholesterol test?

• What are the alternatives to the primary approach that you're suggesting?

• I have other health conditions. How can I best manage them together?

• Are there any restrictions that I need to follow?

• Should I see a specialist?

• If I need medication, is there a generic alternative to the medicine you're prescribing me?

• Are there any brochures or other printed material that I can take home with me?

• What websites do you recommend visiting?

In addition to the questions that you've prepared to ask your doctor, don't hesitate to ask questions during your appointment at any time that you don't understand something.

What to expect from your doctor

Your doctor is likely to ask you a number of questions. Being ready to answer them may reserve time to go over any points you want to spend more time on. Your doctor may ask:

• Do you have a family history of high cholesterol, high blood pressure, or heart disease or strokes?

• What are your diet and exercise habits like?

• Do you smoke? Are you or were you around other smokers?

• Have you had a cholesterol test before? If so, when was your last test? What were your cholesterol levels?

Lifestyle and home remedies

Lifestyle changes are essential to improve your cholesterol level. To bring your numbers down, lose excess weight, eat healthy foods, and increase your physical activity. If you smoke, quit.

Eat heart-healthy foods.

What you eat has a direct impact on your cholesterol level.

• Choose healthier fats. Saturated fat and trans fat raise your total cholesterol and LDL cholesterol. The most common sources of saturated fat in the diet are red meat, processed meats, and dairy products that are not fat-free. Monounsaturated fat—found in olive and canola oils—is a healthier option. Avocados, almonds, pecans, and walnuts are other sources of healthy fat.

• Avoid trans fats. Trans fats, which are often found in margarines and commercially baked cookies, crackers, and snack cakes, are particularly bad for your cholesterol levels. Not only do trans fats increase your total LDL ("bad") cholesterol, but they also lower your HDL ("good") cholesterol. Foods listing "partially hydrogenated oils" in the ingredients contain trans fats.

• Limit your dietary cholesterol. The most concentrated sources of cholesterol include organ meats, egg yolks, and whole milk products. Use lean cuts of meat and skim milk instead. Limit the intake of eggs to no more than seven a week.

• Select whole grains. Various nutrients found in whole grains promote heart health. Choose whole-grain breads, whole-wheat pasta, whole-wheat flour, and brown rice. Oatmeal and oat bran are other good choices.

• Stock up on fruits and vegetables. Fruits and vegetables are rich in dietary fiber, which can help lower cholesterol. Snack on seasonal fruits. Experiment with vegetable-based casseroles, soups, and stir-fries.

• Eat heart-healthy fish. Some types of fish—such as cod, tuna, and halibut—have less total fat, saturated fat, and cholesterol than do meat and poultry. Salmon, mackerel, and herring are rich in omega-3 fatty acids, which help promote heart health.

• Drink alcohol only in moderation. Moderate use of alcohol may increase your levels of HDL cholesterol—but the benefits aren't strong enough to recommend alcohol for anyone who doesn't drink already. If you choose to drink, do so in moderation. This means no more than one drink a day for women and one to two drinks a day for men.

Lose extra pounds.

Excess weight contributes to high cholesterol. Losing even 5 to 10 pounds can help lower total cholesterol levels. Start by taking an honest look at your eating habits and daily routine. Consider your challenges to weight loss—and ways to overcome them. Set long-term, sustainable goals.

Exercise regularly.

Regular exercise can help improve your cholesterol levels. With your doctor's OK, work up to 30 to 60 minutes of exercise a day. Take a brisk daily walk. Ride your bike. Swim laps. To maintain your motivation, keep it fun. Find an exercise buddy or join an exercise group. And you don't need to get all 30 to 60 minutes in one exercise session. If you can squeeze in three to six 10-minute intervals of exercise, you'll still get some benefits. If you are not doing any exercise at all right now, try even 15 minutes of exercise a day several days of the week. Some exercise is much better than no exercise.

Don't smoke.

If you smoke, stop. Cigarette smoking increases your risk of heart disease because it damages your blood vessels and speeds up the accumulation of plaque within arteries.

Prevention

The same heart-healthy lifestyle changes that can lower your cholesterol can help prevent you from having high cholesterol in the first place. To help prevent high cholesterol, you can:

• Eat a low-salt diet that includes many fruits, vegetables, and whole grains

• Limit the amount of animal fats and use good fats in moderation

• Lose extra pounds and maintain a healthy weight

• Quit smoking

• Exercise on most days of the week for at least 30 minutes

• Drink alcohol in moderation, if at all

Updated: 2017-08-15

Publication Date: 2000-07-20