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LDL Cholesterol

LDL stands for Low-Density Lipoprotein.

Cholesterol is a white, waxy substance that is found foods of animal origin; it is also manufactured by all of the cells of our body, but most notably the liver cells. Some cholesterol is essential for good health. Not only is cholesterol an important component of cell walls, it is also essential for the production of certain hormones.

LDL is a lipoprotein that carries large amounts of cholesterol within its core.  LDL cholesterol is often called “the bad cholesterol”.  Elevated LDL can significantly increase the risk for developing premature cardiac disease and stroke in both men and women (and in some cases in children too). When your LDL level is high, this lipoprotein can find its way into the walls of your arteries, blocking the natural flow of blood and leaving you at severe risk for heart attack and stroke.

But fear not – there are several ways in which you can lower your LDL cholesterol.

Diagram of an artery showing plaque buildup

Diagram of an artery along with a symbol representing DNA and an apple representing diet

What are the causes of high LDL Cholesterol?

The main causes of high LDL cholesterol are poor diet and genetics.

It is also important to know that there are certain medical conditions that can lead to cholesterol elevation. These include diabetes and kidney, liver and thyroid disease.  Additionally, certain medications can lead to very elevated cholesterol.  We call these secondary causes of high cholesterol.  If you are found to have high cholesterol, your health care provider will want to rule out these medical conditions and ask you about the medications you are taking.

In the case of diet, the biggest culprit isn’t dietary cholesterol (although it counts), it is foods rich in saturated and trans-fats (see box 3).  Saturated fat and trans fats in the diet lead to a reduction in LDL receptors on cells, especially the liver cells.  LDL receptors are responsible for binding LDL and removing it from your blood.  If your cells can’t remove LDL from the blood, the LDL will eventually find its way into the artery wall forming a plaque.


Genetics and High LDL Cholesterol

As noted above, for some people, it is their genes that lead to very high LDL cholesterol and increased risk of developing heart disease and stroke at an early age.  The two most common causes of genetically high cholesterol are familial hypercholesterolemia (FH), and familial combined hyperlipidemia (FCH).

How to lower your high LDL Cholesterol

How to lower your high LDL Cholesterol

Learn how you can effectively manage your cholesterol.

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What is Familial Hypercholesterolemia?

What is Familial Hypercholesterolemia?

Read about the life-threatening genetic condition that causes high cholesterol.

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How do I know if I have FH?

How do I know if I have FH?

Are your LDL numbers high? Does high cholesterol run in your family?

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Page reviewed by Dr. Mary McGowan