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What is LDL cholesterol?

Let’s start with what cholesterol is. Cholesterol is a white, waxy substance. It’s found in some foods and is also made by all the cells in our body. Most of it is made in your liver.

Our bodies do need some cholesterol. It’s an important part of our cell walls and needed to produce certain hormones.

LDL cholesterol stands for “low-density lipoprotein” cholesterol. LDL is a lipoprotein that carries large amounts of cholesterol in its core. It's often called the “bad cholesterol,” since having too much LDL significantly increases the risk of early heart disease, heart attack, and stroke.

When you have high levels of LDL cholesterol, it can find its way into the walls of your arteries. This blocks the natural flow of blood and causes heart attacks and strokes.

Diagram of an artery showing plaque buildup

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

What causes high LDL cholesterol?

The main causes of high LDL cholesterol come from lifestyle and genetics.


When you look at the nutrition label, you might think the biggest culprit is dietary cholesterol. It counts, but it’s not the worst offender when it comes to high LDL. It’s actually foods with high saturated fats and trans-fats.

Saturated fats and trans-fats reduce LDL receptors that help clean cholesterol out of your bloodstream. If your cells can’t remove LDL from your blood, it finds its way into your arteries, builds plaque, and causes heart attack and stroke.


For some people, genetic disorders can cause very high LDL cholesterol, putting them at greater risk for heart disease and stroke at a very early age.

Familial hypercholesterolemia (FH) is a common, life-threatening genetic disorder affecting the body’s ability to remove LDL cholesterol. If left untreated, FH leads to early heart attack and heart disease.

How low should my LDL be?

In August of 2022, the American College of Cardiology (ACC) released an Expert Consensus Decision Pathway with new guidance for lowering LDL cholesterol.

An Expert Consensus Decision Pathway is a guiding tool for medical professionals. They are developed as new data and treatments are available, but definitive outcome studies are still happening.

The ACC offers new LDL recommendations for different groups of people:

  • For people without heart disease, the LDL safe zone is less than 100 mg/dL.
  • For those who have already experienced a heart attack or stroke, the safe zone is less than 70 mg/dL.
  • For people at very high risk, like those with heart disease and FH, the safe zone is less than 55 mg/dL.
Medical imagery

How to lower your high LDL Cholesterol

Learn how you can effectively manage your cholesterol.

Specialist with family

What is Familial Hypercholesterolemia?

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

Finding an FH Specialist

How do I know if I have FH?

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

Page reviewed by Dr. Mary McGowan