Understanding Cholesterol & Your Blood Work Results

If you’ve had your cholesterol levels checked, you’ve likely been introduced to terms like HDL, LDL and Triglycerides, but do you understand what these terms mean?

In this picture-filled post, you’ll gain an understanding of how your cholesterol numbers are calculated and how cholesterol is handled by your body.

Understanding Cholesterol

Did you know that your body must have cholesterol in order for you to survive?

Cholesterol can be found in the membrane of every cell, and it’s a vital component of hormones like estrogen and testosterone.

So, while we are told that your total cholesterol should be low, you never want it to be zero.

Calculating Your Cholesterol Numbers

Let’s take a look at a typical lab report to better understand what the numbers mean…

Understanding Cholesterol

Total Cholesterol is a calculation that the lab gets by adding your HDL and LDL cholesterol levels together with 20 percent of your triglyceride level.

(Note: you might be wondering why your total cholesterol count includes 20% of your triglycerides. While this complicates the math, the reason is likely due to the fact that VLDLs, which are discussed later, contain a lot of triglycerides. Factoring in a small percentage of triglycerides, may help make the estimate of total cholesterol more accurate.)

Triglycerides, HDL, & LDL

Triglyceride is the scientific name for fat; and, you might know HDL as the “good” cholesterol and LDL as the “bad” cholesterol.

Understanding Cholesterol

HDL and LDL are both lipoproteins…

  • HDL is the abbreviation for High-Density Lipoprotein
  • LDL is the abbreviation for Low-Density Lipoprotein

The term lipoprotein is not one that you hear thrown around in everyday conversation, but it is not a hard term to understand when you break it down into its root words: lipo (short for lipid, which is a fat) + protein.

Understanding Cholesterol

A lipoprotein is, for the most part, a mixed molecule that contains both fats and protein with the fat on the inside, and the protein on the outside.

Because fat and water (blood) don’t mix, fats cannot move through your bloodstream unassisted.

The protein coating of a lipoprotein hides the fat allowing it to float around in your blood.

The Takeaway for Understanding the Lipoproteins HDL & LDL:

The primary job of BOTH “good” HDL and “bad” LDL is to carry cholesterol (a fatty substance) and triglycerides (i.e. fats) through your blood.

It is the direction in which these lipoproteins carry cholesterol that gives them that reputation of being good or bad.

Understanding HDL Cholesterol

The basic fact about HDL is that you want as much as possible.

The best way to keep your cholesterol molecules straight is to think of HDL as the Healthy cholesterol.

HDL’s job is to go out into your body, collect cholesterol, and then return to your liver to drop off its cargo.

understanding cholesterol and hdl

At that point, your liver takes over and either converts the cholesterol into something useful, like a hormone or cell membrane, or it gets turned into bile.

Bile is a substance that helps you digest fats. Once it completes its job, it is excreted out of your body. So, bile is a way your body gets rid of cholesterol.

Understanding LDL

LDL is the cholesterol that gets your attention when you have your blood work checked because of its reputation as the “bad” cholesterol.

LDL works in the opposite direction of HDL. These molecules carry cholesterol to your body.

Understanding Cholesterol HDL & LDL

Your liver makes LDL out of protein, cholesterol, and triglycerides.

When LDL are first created, they are called Very-Low-Density Lipoprotein or VLDL.

VLDL contains some cholesterol, but is mostly filled with triglycerides.

Your body needs those triglycerides for energy, so when VLDL leaves the liver, its cargo quickly gets dropped off at cells that need energy.

With many of the fats gone, the VLDL turns into LDL that contains fewer triglycerides but still has its cholesterol.

Understanding Cholesterol VLDLIf the cholesterol that is contained within the LDL is needed by the body, it is dropped off. If it is not needed, the entire LDL molecule goes back to your liver where it is disassembled, reused, or excreted as bile.

Remember that some cholesterol is needed by your cells to make membranes, so LDL’s can carry cholesterol to your cells…that’s a good use of cholesterol.

However, there is another thing that cholesterol is used as, and this use causes problems.

Cholesterol as a Band-Aid

Cholesterol is a natural Band-Aid when you have a wound within a blood vessel.

Damage within a blood vessel is primarily caused by inflammation.

A common cause of inflammation is a poor diet that contains inflammatory foods, like sugar, refined carbs, and high fructose corn syrup like you get in soda and processed foods. This is one reason why cutting carbs, especially refined carbs is important for your health.

High blood pressure and chronically high insulin levels like we see in a person with diabetes or insulin resistance can also lead to blood vessel damage. Of course, these two conditions are associated with a poor diet.

(Note: Insulin resistance is also seen in women with PCOS. If PCOS and weight gain are issues for you, follow the link for more information.)


You can’t outrun the biological impact of a poor diet. You don’t feel inflammation in your vessels, but it’s happening.

If there is no inflammation within your blood vessels, cholesterol is not needed as a Band-Aid, and therefore, does not build up in the arteries.


Image Credits:

Lipoprotein: AJC1