Once upon a time, the health community believed there was only one kind of cholesterol and that it was universally bad. Nutritionists now recognize that LDL and HDL are two different kinds of cholesterol that play a role in heart health.
Cholesterol Testing
Your cholesterol test begins with giving a blood sample. Health maintenance organization Kaiser Permanente recommends fasting overnight or for several hours prior to giving your sample. Recently eaten food can skew the results, as the digesting food inserts cholesterol and sugar into your bloodstream. Lab tests then analyze your blood for cholesterol content, giving results in milligrams of cholesterol per deciliter of blood.
LDL Cholesterol
LDL, or low-density lipoprotein, cholesterol is the "bad stuff." Although it does play a role in keeping your tissues healthy, it can clump up and block arteries. Ultimately, these clumps can lead to blood clots, heart disease, heart attack and stroke. The lower your LDL level, the better.
HDL Cholesterol
The chief purpose of HDL, high-density lipoprotein, is to carry waste from tissue maintenance back to the liver for disposal. HDL actually cleans LDLs out of the bloodstream, contributing to your overall cardiovascular health. The higher your HDL count, the better your heart health.
Calculating the Ratio
The ratio between your HDL and LDL counts is measured as your "total cholesterol level." To calculate total cholesterol, subtract your HDL from your LDL, then add one-fifth of your triglyceride level. Triglyceride is a third cholesterol only tangentially related to your heart health. In most cases, your cholesterol test will report this cholesterol as well.
Healthy Ratio
The American Heart Association recommends a total cholesterol level of less than 200 milligrams per deciliter. Scores between 200 and 239 are rated as borderline high. Anything above 239 puts you at more than twice the risk of heart disease than somebody with healthy total cholesterol.
References
- "Eat, Drink and Be Healthy"; Dr. Walter Willett, et al; 2006
- "You: The Owner's Manual"; Michael Rozien & Mehmet Oz; 2005
- American Heart Association: Cholesterol Levels
- "Healthwise Handbook"; Kaiser Permanente Publishing; 2009
