Cholesterol is a fatty substance that is essential for the body to function properly. However, when there is too much cholesterol in the blood, it can build up in the walls of the arteries and increase the risk of serious health problems such as heart disease and stroke.

High cholesterol, also known as hypercholesterolemia, is a common medical condition that can be caused by a variety of factors including genetics, a diet high in saturated and trans fats, lack of physical activity, and obesity. High cholesterol often has no symptoms, so the only way to know if you have it is to have a blood test.

The two types of cholesterol are low-density lipoprotein (LDL) and high-density lipoprotein (HDL). LDL cholesterol is often referred to as "bad" cholesterol because it can build up in the arteries, while HDL cholesterol is often referred to as "good" cholesterol because it helps remove LDL cholesterol from the bloodstream.

Treatment for high cholesterol usually involves lifestyle changes and medication. Lifestyle changes such as eating a healthy diet that is low in saturated and trans fats, getting regular exercise, and maintaining a healthy weight can help lower cholesterol. Medications such as statins, bile acid sequestrants, and niacin may also be prescribed to help lower cholesterol.

It is important to have your cholesterol levels checked regularly, particularly if you have a family history of high cholesterol or heart disease. Early diagnosis and treatment of high cholesterol can help prevent serious health complications and improve outcomes.

Cholesterol is carried through your blood, 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

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 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
• Manage stress

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 might recommend medication.

The choice of medication or combination of medications depends on various factors, including your personal risk factors, your age, your 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 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 age 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.