Cholesterol Overview

Cholesterol is produced naturally by the liver, and also comes from eating certain foods, such as eggs and red meat. If you have too much of the wrong kind of cholesterol, it can start to build up in your arteries.

What is Cholesterol?

Cholesterol is a waxy substance made by your liver and found in foods such as meat, dairy, and tropical oils. Though you hear a lot of bad things about cholesterol, and how "high cholesterol" can be dangerous for your heart health, cholesterol in itself isn't bad. In fact, the substance is essential for your entire body.

Cholesterol is important in cell membrane structure and function and acts as a precursor for certain hormones (e.g., estrogen), bile salts (involved in digestion), and vitamin D.

However, when you have too much cholesterol, particularly high levels of a certain type of cholesterol called LDL cholesterol, this puts you at a higher risk for coronary artery disease. Genes, age, sex, race, as well as lifestyle factors related to diet and exercise can make you more prone to developing high cholesterol, a condition that may also be called hypercholesterolemia or dyslipidemia.

Types

There are two main types of cholesterol: LDL and HDL. Your doctor may also talk to you about "non-HDL" cholesterol.

LDL: LDL cholesterol stands for low-density lipoprotein and is referred to as "bad" cholesterol. That's because it contributes to the buildup of plaque, a combination of fat, cholesterol, and calcium, which gunks up arteries to block blood flow. When blood flow is blocked, you can have a heart attack or stroke. Ideally, you have a low LDL level.

HDL: HDL cholesterol stands for high-density lipoprotein. Its nickname is "good" cholesterol because HDL protects the heart. The job of HDL is to ferry a portion of LDL cholesterol away from the heart and to the liver where it can be flushed from the body. It's best to have a higher HDL level. Low levels increase heart disease risk.

Total Cholesterol: While this isn't a type of cholesterol, you will hear your doctor talk about this term. It's based on your LDL, HDL, and a portion of your triglyceride level.

Non-HDL: Stands for total cholesterol minus your HDL. This number includes LDL and VLDL cholesterol, which stands for very-low-density lipoprotein. The job of VLDL cholesterol is to carry triglycerides, a type of fat in your blood, to your tissues. High levels also increase the risk of a heart attack and stroke.

Symptoms of High Cholesterol

Unfortunately, there are little to no warning signs that you have high cholesterol levels. In certain severe cases, particularly if extremely high cholesterol runs in the family (a condition called familial hypercholesterolemia), you may notice a couple of physical signs:

Xanthoma: A condition where fats accumulate under the surface of the skin. These bumps can range in size—up to three inches—and may be found on your elbows, knees, hands, feet, or buttocks.

Corneal arcus: A white, light grey, or blueish ring around the edge of the cornea that's primarily made of cholesterol deposits. Your eye may look like two different colors.

Causes

When it comes to the causes of high cholesterol, there are some factors you can control, such as lifestyle, and others that are out of your control, like your genes:

Genetics or family history. Certain genetic mutations can affect the body's ability to recycle LDL cholesterol. Called familial hypercholesterolemia, those with this genetic defect can have extremely high LDL levels. This type of high cholesterol also leaves you vulnerable for heart disease. Having a strong family history of high cholesterol may suggest that you're at risk as well, if you share similar lifestyle behaviors.

Age. Aging causes cholesterol clearance to become more sluggish, so you're more at risk for high cholesterol the more birthday candles on your cake.

Your diet. A diet rich in saturated fats (which come from animal foods like meat and dairy, and tropical oils) or trans fat increase levels of LDL cholesterol

Sedentary lifestyle. A lack of physical activity is linked to lower "good" HDL cholesterol levels.

Smoking and excessive drinking. These habits raise total and "bad" LDL cholesterol and/or lower "good" HDL cholesterol.

Stress. Chronic stress increases levels of cortisol in the body, which triggers the production of cholesterol.

Medical conditions. Certain medical conditions, such as having diabetes or obesity, may negatively impact cholesterol levels.

Medications. A side effect of some medications, such as steroids and beta blockers, may raise LDL or lower HDL cholesterol.

Diagnosis

A simple blood test will measure your cholesterol levels. This test may be ordered if you may be at risk for high cholesterol or it may be done as part of a health screening. You may need to take the blood test after fasting (meaning you will not be able to eat prior to the test. (Be sure to take it in the morning before breakfast.) This test is called a lipid panel, and it may measure:

• Total cholesterol
• LDL cholesterol
• HDL cholesterol
• Triglycerides

Your doctor may be concerned if you have cholesterol numbers that are not normal, which can indicate that you're at a higher risk for heart disease.

Healthy cholesterol is defined as:

Total cholesterol: Less than 200 mg/dL
LDL cholesterol: Less than 100 mg/dL
HDL cholesterol: Greater than or equal to 60 mg/dL

Treatment

Depending on the cause of your high cholesterol, your doctor may suggest lifestyle changes or medication.

Healthy Diet. Habits that will help bring down high cholesterol include diet and exercise. Start by eating less saturated fat, aiming to consume no more than 6% of your total daily calories from this type of unhealthy fat. You'll find sat fat in red meat, hot dogs and sausages, butter, cheese, full-fat milk, cream, tropical oils such as coconut, many desserts, fast food, and pizza. Focusing on eating more whole grains, vegetables and fruits, legumes, and heart-healthy sources of fat like olive oil, will improve heart health, including cholesterol levels.

Exercise. The great news is that physical activity boosts levels of your "good" HDL cholesterol, which will ultimately help get LDL out of your blood. Aim for 150 minutes per week of moderate-intensity exercise.

Weight loss. Being overweight or having obesity is associated with poor cholesterol levels. Losing a small amount of weight can help decrease LDL and increase HDL.

Quit smoking. Stopping smoking is one of the most powerful things you can do to immediately cause an increase in your healthy HDL cholesterol.

Medication. If your doctor decides that a medication will be helpful to treat your high cholesterol—because lifestyle changes aren't enough or you have familiar hypercholesterolemia—they can prescribe:

• Statins
• Cholesterol absorption inhibitors (ezetimibe)
• Bile acid sequestrants
• PCSK9 inhibitors
• Fibrates
• Niacin
• Omega-3 Fatty Acid Ethyl Esters

Prevention

Having a heart-healthy lifestyle—diet, exercise, managing stress, sleeping well, avoiding smoking and limiting alcohol consumption—will go a long way in keeping your cholesterol levels in the right range.

In addition, regular, appropriate screening for high cholesterol can help you catch cholesterol problems early so that they can be treated so you can reduce the risk of potential consequences of dyslipidemia, including coronary artery disease.

Screening includes a lipid panel, which will provide total cholesterol, LDL, and HDL cholesterol numbers. This is done with a simple blood test. Healthy adults should get their cholesterol checked every four to six years.

To get our top stories delivered to your inbox, sign up for the Healthy Living newsletter