Believe it or not, cholesterol isn't all bad. This soft, waxy substance, which is manufactured in the liver and also found in animal products, helps produce hormones, vitamin D and the bile acids needed to digest fat. The catch: It takes just a tiny amount of cholesterol to do all this, and the excess cholesterol in your bloodstream can lead to atherosclerosis. This condition, in which artery walls become clogged and narrowed, is a major cause of heart disease or stroke.
So keeping your cholesterol numbers in check is every bit as important as keeping an eye on the speedometer when you're on the freeway. But it's a bit more complicated. Here's what you need to know and some steps you can take:
Types of Cholesterol
Like oil and water, cholesterol (which is fatty) and blood (which is watery) don't mix well. So cholesterol travels through the bloodstream, along with protein, in packages called lipoproteins. Different kinds of lipoproteins affect your heart-disease risk in different ways:
What Do the Numbers Mean?
It's important to know not only your total cholesterol but also your individual HDL and LDL levels to fully understand your risk of heart disease (see chart below). You should strive for a total cholesterol level of below 200, an HDL level above 35 and an LDL level below 130. In general, if your total or your LDL cholesterol level is higher than these figures, you are at increased risk for heart disease and should consider lifestyle changes to lower your cholesterol. If your total cholesterol level is 240 or higher, your HDL level is below 35 or your LDL level is 160 or higher, you are at high risk for heart disease and should work with your doctor to develop a treatment plan that's right for you.
How Are Your Cholesterol Levels?
| Desirable | Borderline | Undesirable | |
| Total cholesterol | Less than 200 | 200-239 | 240 or higher |
| HDL cholesterol | Less than 35 | ||
| LDL cholesterol | Less than 130 | 130-159 | 160 or higher |
Source: National Heart, Lung, and Blood Institute
Cholesterol Testing
Knowing your family medical history can help you determine your risk of developing high cholesterol and possible heart disease. "If your parents, uncle, aunt or other close relative developed heart disease at an early age, you're in a high-risk group and should be tested," says Rodman Starke, M.D., executive vice president for science and medicine for the American Heart Association (AHA).
For a person with a family history of heart disease, Starke recommends cholesterol testing (a simple blood test) beginning in the teens. People with no such family history should be tested at about age 20. If levels are normal, the test should be repeated every five years.
Lowering Your Cholesterol
Want to bring your numbers down? Here are some tips from the AHA and the National Heart, Lung, and Blood Institute: