A simple blood test can reveal the hidden details of your cholesterol. But knowing what the numbers mean is not so simple.
Types of cholesterol measured
You would think that a lab test for cholesterol would simply tell you how much cholesterol you have. And it does, but wait: There are several cholesterol measurements. These are:
- Total cholesterol
- HDL cholesterol
- LDL cholesterol
HDL cholesterol is the "good" cholesterol. It's carried on high-density lipoproteins. Having more of it means you're more likely to have a lower risk of coronary heart disease (CHD).
LDL cholesterol is the "bad" cholesterol. It's carried on low-density lipoproteins. You're better off with lower levels of LDL cholesterol, because it's linked to a higher risk of heart disease.
Note that total cholesterol does not equal HDL cholesterol plus LDL cholesterol. This is because there are still more types of cholesterol, which we won't talk about here.
Your cholesterol numbers
Cholesterol is measured as milligrams of cholesterol per deciliter of blood, which is abbreviated like this: mg/dL.
A lipid profile test (total cholesterol, HDL cholesterol and triglycerides) is done after a 9 to 12 hour fast. The HDL, total cholesterol and triglycerides can be measured and then the LDL can be calculated using these numbers.
Here is what the levels mean.
If your total cholesterol is:
|200 mg/dL or less||Desirable cholesterol level|
|Between 200 and 239 mg/dL||Borderline high cholesterol level|
|240 mg/dL or more||High|
If your HDL cholesterol is:
|Less than 40 mg/dL||Too low|
|60 mg/dL or higher||High- Beneficial|
The goal for your LDL level depends on your other risk factors for heart disease.
If you are 20 years old or older, have no heart disease and your LDL cholesterol is:
|Less than 100 mg/dL||Desirable|
|100 - 129 mg/dL||Near optimal/above optimal|
|130 - 159 mg/dL||Borderline high|
|160 - 189 mg/dL||High|
|190 mg/dL and above||Very high|
If you already have heart disease, diabetes or problems with your circulation, then your LDL cholesterol should be 100 mg/dL or less.
Triglycerides are another fatty substance in the blood that affects your risk for heart disease. Most fat in food, as well as in your body, is present in the form of triglycerides. High levels are a matter of concern and are linked to the risk of heart disease, just as with cholesterol.
Elevated triglycerides are common. Triglycerides may be elevated even if the total and HDL cholesterol are normal. So there is no way to know if a person has high triglycerides unless it is measured.
If your triglycerides are tested, here is how you can interpret the numbers, according to the Third Report of the Expert Panel on the Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults:
|Less than 150 mg/dL||Normal|
|150 - 199 mg/dL||Borderline|
|200 - 499 mg/dL||High|
|More than 500 mg/dL||Very high|
The American Heart Association now suggests that a triglyceride level below 100 mg/dL is optimal.
Screening for high cholesterol is advised for everyone 20 years or age or older. Remember, only your doctor should decide the best way to evaluate and interpret your cholesterol levels. Speak to your doctor if you have any questions about your cholesterol levels. Also discuss with the doctor the best way, given your unique needs, to reduce your risk for heart disease.
Created on 06/08/1999
Updated on 12/01/2011
- National Institutes of Health. Third report of the national cholesterol education program (NCEP). Detection, evaluation and treatment of high blood cholesterol in adults.
- Miller M, Stone NJ, Ballantyne C, et al. Triglycerides and cardiovascular disease: a scientific statement from the American Heart Association.