According to the American Heart Association (AHA), total levels of blood cholesterol under 200 milligrams per deciliter represent a low risk for coronary heart disease. Levels between 200 and 240 are considered to be borderline risk, and over 240 is considered dangerously high risk. While total levels of blood cholesterol are considered important, other factors come into play, as well. For example, if someone has a borderline-high total cholesterol level, but has very low levels of HDL, the "good" cholesterol, he or she may still have a high risk of heart disease. In general, doctors worry about the ratio of LDL (the "bad" cholesterol) to HDL. A desirable HDL level is over 50, according to W. Virgil Brown, M.D. For LDL, a level below 130 is desirable, 130 to 160 is borderline high, and over 160 represents a high risk of heart disease, he says. Although these numbers aren't absolute (for example, levels of triglycerides, another fatty acid, also enter into the big picture), they do represent a fairly good predictor of heart disease risk, according to Brown. "We know that, on average, for every one percent increase in total blood cholesterol, there is a two to three percent increase in heart disease rates," he says. "For a person with a total cholesterol of 220, their risk is ten percent higher than a person with a total cholesterol of 200. A person with a level of 250 has a 50 percent higher risk than the person with 200."
Heart Smart Glossary
The following are definitions of terms commonly used in discussions of cholesterol and cardiovascular health:
LDL: Low-density lipoprotein, the "bad" cholesterol often implicated in the development of atherosclerosis
HDL: High-density lipoprotein, the "good" cholesterol thought to protect against atherosclerosis
Triglycerides: Another type of fatty acid found in the blood that doctors measure when they evaluate heart-disease risk