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NIH MedlinePlus the Magazine, Trusted Health Information from the National Institutes of Health

High Cholesterol

Understanding Cholesterol and Heart Health

Many Americans do not understand the role that cholesterol—a fat-like substance found in all cells of the body—plays in heart health and heart disease. When there is too much cholesterol in the blood, cholesterol can build up on artery walls and slow or stop blood flow to the heart. Here's what you need to know . . .

The liver (upper left) produces cholesterol (bottom). We also get cholesterol from what we eat, especially meat and dairy products.

The liver (upper left) produces cholesterol (bottom). We also get cholesterol from what we eat, especially meat and dairy products. Illustration: iStockphoto

To understand high blood cholesterol it helps to learn about cholesterol, a waxy, fat-like substance found throughout the body.

Our bodies need some cholesterol to make hormones, vitamin D, and substances that help digest foods. Our bodies make all the cholesterol we need. However, cholesterol also is found in some of the foods we eat.

Cholesterol travels through the bloodstream in small packages called lipoproteins. These packages are made of fat (lipids) on the inside and proteins on the outside. Two main kinds of lipoproteins carry cholesterol throughout the body:

  • Low-density lipoproteins (LDL): LDL cholesterol sometimes is called "bad" cholesterol. A high LDL level leads to a buildup of cholesterol in your arteries. (Arteries are blood vessels that carry blood from your heart to your body.)
  • High-density lipoproteins (HDL): HDL cholesterol sometimes is called "good" cholesterol. This is because HDL carries cholesterol from other parts of your body back to your liver. Your liver removes the cholesterol from your body.

Having healthy levels of both types of lipoproteins is important.

High Blood Cholesterol and Triglycerides

High blood cholesterol is a condition in which you have too much cholesterol in your blood. By itself, the condition usually has no signs or symptoms. So, many people don't know that their cholesterol levels are too high.

People who have high blood cholesterol have a greater chance of getting coronary heart disease, also called coronary artery disease. Coronary heart disease is a condition in which plaque builds up inside the coronary (heart) arteries. Plaque is made up of cholesterol, fat, calcium, and other substances found in the blood. When plaque builds up in the arteries, the condition is called atherosclerosis. Atherosclerosis can lead to serious problems, including heart attack, stroke, or even death. The higher the level of LDL cholesterol in your blood, the GREATER your chance is of developing heart disease. The higher the level of HDL cholesterol in your blood, the LOWER your chance is of developing heart disease.

On the Cover

Celebrities today are not shy about reporting their struggles with heart disease—whether it is a heart attack, heart surgery, or a stroke.
This issue's cover celebrities have all had heart problems of one kind or another. As a result, they often speak out about heart health.

Cover illustration of a heart
  1. Miley Cyrus: Non-life threatening rapid heartbeat (tachycardia).
  2. Bruce Johnson: Veteran television journalist survives a heart attack at 42.
  3. Bill Clinton: 90% artery blockage led to 2004 heart surgery and much healthier diet.
  4. Dick Cheney: A smoker for almost 20 years, he had the first of five heart attacks at age 37.
  5. Barbara Walters: ABC journalist had heart valve replacement surgery in 2010.
  6. Star Jones: Signs of heart disease helped her lose weight and have heart surgery.
  7. Robin Williams: Heart valve replacement surgery corrected an irregular heartbeat.
  8. Toni Braxton: High blood pressure and a heart flutter helped the singer adopt healthier eating and exercise.
  9. Jennie Garth: A family history of heart disease and a leaky heart valve have the actress on her guard.
  10. Shaun White: Born with a heart defect, the Olympic snowboarder had two heart operations to overcome the challenges.


New Cholesterol Recommendations Expected by End of 2012

In May of this year, an important study on HDL cholesterol was published in The Lancet medical journal, questioning its beneficial effects concerning heart disease.

The study tested the hypothesis that genetically raised HDL (good) cholesterol might protect against heart attack. The authors concluded that some genetic mechanisms that raise HDL cholesterol do not appear to lower the risk of heart attack. "This outstanding research provides some insight as to why HDL clinical trials have been disappointing," says Michael Lauer, M.D., director of the Division of Cardiovascular Sciences at the National Heart, Lung, and Blood Institute (NHLBI).

New clinical practice guidelines on the detection, evaluation, and treatment of high blood cholesterol are expected be released at the end of 2012. These guidelines will be available at

Read More "Cholesterol and Hearth Health" Articles

Understanding Cholesterol and Heart Health / High Blood Cholesterol Q&A / Cholesterol Levels: What You Need to Know / All In The Family

Summer 2012 Issue: Volume 7 Number 2 Page 4