What Is High Cholesterol? Symptoms, Causes, Diagnosis, Treatment, and Prevention

High cholesterol is a condition that occurs when levels of cholesterol in your blood are elevated enough to cause health problems, including heart disease and stroke.  Sometimes known as hyperlipidemia, high cholesterol is painless and doesn’t cause any symptoms until a person develops severe heart disease.

According to the Centers for Disease Control and Prevention (CDC), heart disease is the leading cause of death in the United States, and stroke is the fifth leading cause.

Produced by your liver, cholesterol is a dense, fatty substance that’s found in every cell of your body, and it is considered essential to many life-sustaining functions. It helps your body make hormones and vitamin D, and it's also found in compounds that your body creates to help you digest food, such as bile.

Circulating in the bloodstream in small bundles of fat and protein called lipoproteins, cholesterol comes in two primary types: low-density lipoprotein (LDL), which contributes to the buildup of fatty plaques, and high-density lipoprotein (HDL), which is thought to protect from heart disease and stroke.  A blood test known as a lipid panel can measure both LDL and HDL cholesterol, as well as triglycerides, the most common type of fat in the blood.

Typically, high cholesterol doesn’t cause any symptoms until it causes a medical emergency, like a heart attack or stroke. These heart-disease-related events don’t occur until high cholesterol levels have led to fatty plaque building up in the arteries. In turn, this leads to a narrowing of the arteries and a change in the makeup of the arterial lining, also known as heart disease.

Heredity

Having a family history of high cholesterol or heart disease also means you are more likely to have high cholesterol.

Although it is relatively rare, some people also carry a genetic condition called familial hypercholesterolemia, which causes extremely high LDL levels at a young age and, if left untreated, can lead to early-onset coronary artery disease and heart attacks. The CDC estimates that 1 million Americans, or a third of a percent of the U.S. population, have familial hypercholesterolemia.

Age

Due to age-related metabolic changes, including how the liver removes LDL cholesterol from the blood, everyone’s risk of high cholesterol increases as they get older.

Gender

Women over 55 or who have completed menopause tend to have lower LDL cholesterol levels than men. In general, men tend to have higher HDL cholesterol levels than women.

Diet

Level of Physical Activity

Tobacco Use

Obesity

Diabetes

Since high cholesterol alone typically has no signs or symptoms, the only way to find out if you have it is to get a simple blood test known as a lipid profile, or lipid panel. This blood test might require you to fast (not eat or drink) for 8 to 12 hours before your blood is drawn.

From this blood sample, your doctor can measure your LDL cholesterol, HDL cholesterol, and triglycerides, which at high levels can combine with low HDL or high LDL to increase your risk of heart disease. A lipid panel can also tell you your total cholesterol, which is based on all three components.

• LDL cholesterol of less than 100 milligrams per deciliter (mg/dL)
• HDL cholesterol that's greater than or equal to 60 mg/dL
• Triglycerides of less than 150 mg/dL
• Total cholesterol of less than 200 mg/dL

However, more and more cardiologists are focusing less on specific numbers and more on overall risk of heart disease, according to Peter Schulman, MD, an attending cardiologist and professor of medicine at UConn Health in Farmington, Connecticut. Your age and overall health can help you determine whether you should talk to your doctor about improving your cholesterol levels if they’re not in the desirable range.

Although having high cholesterol numbers can contribute to the long-term risk of heart attack and stroke, you can lower your cholesterol through changes in your lifestyle habits, including adopting a heart-healthy diet, increasing your physical activity level, and quitting smoking. These long-term lifestyle changes can also prevent your cholesterol levels from changing in the first place.

Learn More About Prevention of High Cholesterol

Medications to Treat High Cholesterol

For most people who need medication to manage high cholesterol, doctors will prescribe statins. Statins, also known as HMG CoA reductase inhibitors, are a class of drugs that prevent cholesterol from forming in the liver, where both LDL and HDL cholesterol are made. This lowers the amount of cholesterol circulating in the blood. They are most effective at lowering LDL cholesterol but can also lower triglycerides and HDL cholesterol.

If you have certain conditions, or if statins aren’t working to decrease your high cholesterol sufficiently, your doctor may prescribe one of these other cholesterol-lowering medications:

• PCSK9 Inhibitors A newer type of medicine, PCSK9 inhibitors bind to and inactivate a protein on certain liver cells, which then lowers LDL cholesterol. Administered by injection, they are often used in patients with high cholesterol that doesn’t respond to statins or people with familial hypercholesterolemia.

  

• Selective Cholesterol Absorption Inhibitors The most commonly used nonstatin agent, according to the AHA, selective cholesterol absorption inhibitors prevent cholesterol from being absorbed in the intestine. This means less cholesterol is delivered to the liver and, ultimately, the blood.

  

• Bile Acid Sequestrants Also known as bile-acid-binding agents, these drugs work by removing bile acids from the liver. Since LDL cholesterol is needed to make bile acids, the body then breaks down more LDL cholesterol particles.

Although the data doesn’t support the ability of these drugs to directly lower LDL and total cholesterol, your doctor may prescribe the following drugs to manage your triglyceride levels:

• Fibrates These medications reduce overall triglyceride levels by reducing the liver’s production of very-low-density lipoproteins, which are made up mostly of triglycerides.
• Niacin Also known as nicotinic acid, niacin is a B vitamin that can raise HDL cholesterol while lowering levels of total cholesterol, LDL cholesterol, and triglycerides.
• Omega-3 Fatty Acid Supplements In large doses, omega-3 fatty acids can help lower triglyceride levels. The most common supplement is OTC fish oil, but they are also available by prescription.

Learn More About Treatment for High Cholesterol: Medication, Lifestyle Changes, and More

Regularly monitoring your cholesterol levels can also help prevent your numbers from getting too high or low. In general, healthy adults should check their cholesterol every four to six years, but your doctor may ask to check your cholesterol more often depending on your age, overall health, and other risk factors. There are other ways to prevent high cholesterol, too

Eat a Healthy Diet

Eating a diet low in saturated and trans fat and high in fiber and unsaturated fats can help prevent high cholesterol. Foods like oatmeal, beans, avocados, and vegetable oils can lower LDL cholesterol and increase HDL cholesterol levels.

Get Regular Physical Activity

Quit Smoking

Maintain a Normal Weight

Having a BMI in the overweight or obese range highly correlates with having excess body fat, which in turn can affect how your body processes cholesterol. Excess body fat also slows down the ability to remove LDL cholesterol from the blood, raising your levels and increasing your risk of heart attack and stroke.

Limit Alcohol Intake

Since high cholesterol alone typically doesn’t cause any symptoms, people only experience complications when their high cholesterol contributes to the development of severe heart disease, often in the form of heart attack or stroke. Over the long term, high cholesterol can cause plaque to form in your arteries, which can then narrow and lead to a cardiovascular emergency.

Heart disease is the leading cause of death in the United States, and stroke is the fifth leading cause.

• Overall, HDL cholesterol levels were lowest in Black Americans and highest in people identifying as of Hispanic origin, a category that includes many who identify as Chicano or Latinx.
• Across all racial and ethnic groups, women had a lower prevalence of low HDL cholesterol than men.

High cholesterol is associated with other medical conditions:

• High Blood Pressure High cholesterol is linked to high blood pressure because cholesterol-filled plaques can narrow arteries, forcing the heart to pump harder.

  

• Heart Disease Without management, high cholesterol contributes to the development of heart conditions like heart attack and peripheral arterial disease.
• Stroke If left untreated over the long term, high cholesterol contributes to the risk of stroke, a type of severe blood clot or blockage of blood flow to the brain.
• Type 2 Diabetes People with diabetes tend to have high LDL and low HDL cholesterol levels, as well as higher levels of triglycerides.