When the heart's blood vessels become clogged with cholesterol, it sets the stage for a heart attack, and this year, nearly half a million Americans will die from heart disease, according to the American Heart Association (AHA). What's more, due in part to rising obesity rates and the popularity of fast food, heart-attack victims are getting younger and younger. It should come as no surprise, then, that high cholesterol is increasingly being referred to as a silent killer.

Stay Home or Leave It to the Lab?

An estimated 105.2 million American adults have total blood cholesterol values of 200 mg/dL and higher, and of these, about 36.6 million have levels of 240 or above. In adults, total cholesterol levels of 240 mg/dL or higher are considered high risk, while levels from 200 to 239 mg/dL are considered borderline-high risk, according to the AHA.

If you're 20 years of age or older, your cholesterol levels should be tested every five years and possibly more often if you already have high cholesterol. With medical costs rising, you might be tempted to try home cholesterol tests purchased from a pharmacy or via the Internet. But are they worth it?

Home cholesterol tests are generally 95 percent accurate, according to the U.S. Food and Drug Administration (FDA), which approved such tests in 1993. The home accuracy rates are on par with the rates of professional lab exams. The FDA also points out that home tests claiming to be traceable to the Centers for Disease Control and Prevention may be more accurate than others.

The D.I.Y Downside

That said, home cholesterol tests don't come without their problems. Most of them measure only total cholesterol, not your full cholesterol profile, which includes HDL, LDL, and triglycerides. Plus, it's always best for a doctor to review test results in conjunction with your other risk factors, such as family history, nutritional habits, age, and gender, to make a truly informed diagnosis and treatment recommendations.

What's more, to get an accurate reading, patients need to fast before their test. But all too often, patients forget to stop eating without their doctors' instruction.

Perhaps most surprisingly, although home tests may be faster and more convenient, they might not offer much of a savings after all. Nowadays, home cholesterol tests cost anywhere from $15 for a standard kit to $200 for sophisticated digital monitoring. Meanwhile, full-profile tests conducted at the doctor's office and any needed follow-up tests cost about $30 each. In addition, most health insurance companies cover those costs but home kits are not covered.

For these reasons, most experts recommend skipping the at-home tests. You may save some time, but taking a trip to the doctor is still the best way to gauge your cholesterol levels and reduce your disease risk.