High cholesterol: Symptoms and causes

Overview

Cholesterol is a waxy substance found in your blood. Your body needs cholesterol to build healthy cells, but high levels of cholesterol can increase your risk of heart disease.

With high cholesterol, you can develop fatty deposits in your blood vessels. Eventually, these deposits grow, making it difficult for enough blood to flow through your arteries. Sometimes, those deposits can break suddenly and form a clot that causes a heart attack or stroke.

High cholesterol can be inherited, but it's often the result of unhealthy lifestyle choices, which make it preventable and treatable. A healthy diet, regular exercise, and sometimes medication can help reduce high cholesterol.

Symptoms

High cholesterol has no symptoms. A blood test is the only way to detect if you have it.

When to see a doctor

According to the National Heart, Lung, and Blood Institute (NHLBI), a person's first cholesterol screening should occur between the ages of 9 and 11 and then be repeated every five years after that.

The NHLBI recommends that cholesterol screenings occur every one to two years for men ages 45 to 65 and for women ages 55 to 65. People over 65 should receive cholesterol tests annually.

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

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Causes

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

Low-density lipoprotein (LDL).

LDL, the "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, the "good" cholesterol, picks up excess cholesterol and takes it back to your liver.

A lipid profile also typically measures triglycerides, a type of fat in the blood. Having a high triglyceride level also can increase your risk of heart disease.

Factors you can control — such as inactivity, obesity, and an unhealthy diet — contribute to harmful cholesterol and triglyceride levels. Factors beyond your control might play a role, too. For example, your genetic makeup might make it more difficult for your body to remove LDL cholesterol from your blood or break it down in the liver.

Medical conditions that can cause unhealthy cholesterol levels include:

Chronic kidney disease
Diabetes
HIV/AIDS
Hypothyroidism
Lupus

Cholesterol levels can also be worsened by some types of medications you may be taking for other health problems, such as:

Acne
Cancer
High blood pressure
HIV/AIDS
Irregular heart rhythms
Organ transplants

Risk factors

Factors that can increase your risk of unhealthy cholesterol levels include:

Poor diet.

Eating too much saturated fat or trans fats can result in unhealthy cholesterol levels. Saturated fats are found in fatty cuts of meat and full-fat dairy products. Trans fats are often found in packaged snacks or desserts.

Obesity.

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

Lack of exercise.

Exercise helps boost your body's HDL, the "good," cholesterol.

Smoking.

Cigarette smoking may lower your level of HDL, the "good," cholesterol.

Alcohol.

Drinking too much alcohol can increase your total cholesterol level.

Age.

Even young children can have unhealthy cholesterol, but it's much more common in people over 40. As you age, your liver becomes less able to remove LDL cholesterol.

Complications

High cholesterol can cause a dangerous accumulation of cholesterol and other deposits on the walls of your arteries (atherosclerosis). 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 might have chest pain (angina) and other symptoms of coronary artery disease.

Heart attack.

If plaques tear or rupture, a blood clot can 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, a stroke occurs when a blood clot blocks blood flow to part of your brain.

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 emphasizes fruits, vegetables, and whole grains
Limit the number 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
Manage stress

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

Generally, you're required to fast, consuming no food or liquids other than water, for nine to 12 hours before the test. Some cholesterol tests don't require fasting, so follow your doctor's instructions.

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.

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 then be repeated every five years after that.

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

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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 significant lifestyle changes and your cholesterol levels remain high, your doctor might recommend medication.

The choice of or combination of medications depends on various factors, including your personal risk factors, age, health, and possible drug 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. Choices include atorvastatin (Lipitor), fluvastatin (Lescol), lovastatin (Altoprev), pitavastatin (Livalo), pravastatin (Pravachol), rosuvastatin (Crestor) and simvastatin (Zocor).

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 with a statin drug.

Bempedoic acid.

This newer drug works in much the same way as statins but is less likely to cause muscle pain. Adding bempedoic acid (Nexletol) to a maximum statin dosage can help lower LDL significantly. A combination pill containing both bempedoic acid and ezetimibe (Nexlizet) also is available.

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.

PCSK9 inhibitors.

These drugs can help the liver absorb more LDL cholesterol, which lowers the amount of cholesterol circulating in your blood. Alirocumab (Praluent) and evolocumab (Repatha) might 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 an intolerance to statins or other cholesterol medications. They are injected under the skin every few weeks and are expensive.

Medications for high triglycerides

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

Fibrates.

The medications fenofibrate (Tricor, Fenoglide, others) and gemfibrozil (Lopid) reduce your liver's production of very-low-density lipoprotein (VLDL) cholesterol and speed the removal of triglycerides from your blood. VLDL cholesterol contains mostly triglycerides. Using fibrates with a statin can increase the risk of statin side effects.

Niacin.

Niacin limits your liver's ability to produce LDL and VLDL cholesterol. But niacin doesn't provide additional benefits over statins. Niacin has also been linked to liver damage and strokes, 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. 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 of statins are muscle pains and muscle damage, reversible memory loss and confusion, and elevated blood sugar. If you decide to take cholesterol medication, your doctor might 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 aged 2 and older who have high cholesterol or who are obese. Children age 10 and older who have extremely high cholesterol levels might be prescribed cholesterol-lowering drugs, such as statins.

Lifestyle and home remedies

Lifestyle changes are essential to improve your cholesterol levels.

Lose extra pounds. Losing weight can help lower cholesterol.
Eat a heart-healthy diet. Focus on plant-based foods, including fruits, vegetables, and whole grains. Limit saturated fats and trans fats. Monounsaturated fat, found in olive and canola oils, is a healthier option. Avocados, nuts, and oily fish are other sources of healthy fat.
Exercise regularly. With your doctor's OK, work up to at least 30 minutes of moderate-intensity exercise five times a week.
Don't smoke. If you smoke, find a way to quit.

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