LDL cholesterol has gotten a bad reputation, and for very good reason. Having too much of this fatty substance in your blood can clog up your arteries, preventing blood from getting to your heart and out to where it's needed in your body. Checking your LDL levels can help your doctor spot high cholesterol before it can cause a heart attack or stroke. Let's talk today about LDL tests.

LDL stands for "low-density lipoprotein." Lipoprotein is a type of protein that transports cholesterol, as well as fats called triglycerides and lipids, in your blood. When you eat too many fatty, cholesterol-rich foods, LDL cholesterol can start to collect in your artery walls. That's one collection you don't want, because if a chunk of that gunk breaks loose and gets lodged in a blood vessel, you could end up having a heart attack or stroke.

To check your LDL cholesterol level, you'll need to have a blood test. Your doctor may tell you not to eat or drink anything for 8 to 12 hours before the test, so you can get an accurate reading.

During the test, your doctor will draw blood from one of your veins. The needle might sting a little bit, but the feeling shouldn't last for any more than a few seconds.

So, how do you know that you have high LDL cholesterol?

Well, your LDL cholesterol level (think: L for Lousy) will usually be measured along with your HDL, or good cholesterol (think: H for Healthy), as well as your triglycerides and your total cholesterol level. Together, these measurements are called a lipid panel.

You want your LDL level to be at least below 130 mg/dl, but ideally less than 100 milligrams per deciliter. If you're at high risk of heart disease, it should be even lower than that -- less than 70 milligrams per deciliter. And for folks of average risk of getting heart disease, anything over 160 is considered a high LDL level.

If you do have LDL cholesterol, you could be at risk for heart disease. Now, some folks have high cholesterol because they have an inherited condition that causes high cholesterol. If your LDL is low, it may be because you're not eating a well-balanced diet or your intestines aren't absorbing the nutrients from the foods that you eat.

Ask your doctor how often you should have your LDL, and total cholesterol levels, checked. Depending upon your heart disease risks, you may need to be tested more often. If your LDL cholesterol is high, ask your doctor about cholesterol-lowering medications, diet, and other ways to bring it back down into a normal range.