You've probably heard that high cholesterol levels in the blood raise the risk for heart disease and stroke. What are high cholesterol numbers and what makes them high? September happens to be National Cholesterol Education Month, so now is the time to provide education about what cholesterol is, what your numbers mean, and how to maintain cholesterol in the normal range. It's also a reminder to get screened.

Cholesterol is a waxy-like substance produced by the body and found in animal products such as meat and high-fat dairy products. Cholesterol has gotten a bad rap; however, it is crucial for keeping your body healthy by aiding the body's production of vitamin D and hormones, helping digest food, and providing a coating for cells. It is important to note that our bodies produce enough cholesterol, without consuming it, to function properly. When there is too much cholesterol in the blood stream arteries become clogged, raising the risk for heart attack and stroke.

I'm sure you've heard about "bad" cholesterol and "good" cholesterol. What is the difference? Low-density lipoprotein (LDL) is known as the "bad" cholesterol because it carries excess cholesterol in the bloodstream and deposits it in arteries, leading to blockage. High-density lipoprotein (HDL) is known as the "good" cholesterol because it sweeps excess cholesterol from the cells and bloodstream and delivers it back to the liver for recycling.

A cholesterol test is a blood test measured as milligrams (mg) of cholesterol per deciliter (dL) of blood. When you are screened, you receive numbers for total cholesterol, LDL, and HDL levels. Desirable total cholesterol measures less than 200 mg/dL; a number of 240 mg/dL is considered high. Anything between is considered borderline high. An LDL level of 100 mg/dL or less and an HDL level of 60 mg/dL or more are considered protective against heart disease and stroke. Target total cholesterol, LDL, and HDL numbers should mimic those normal levels mentioned above, but your doctor may have different target levels for you if you have other risk factors contributing to heart disease, such as diabetes.

High cholesterol can be an inherited trait, meaning that your body producing too much cholesterol, especially LDL, can run in your family. This is an uncontrollable factor. A controllable factor is consuming a diet high in cholesterol, and especially saturated fat, which is a major contributor to cholesterol levels. This is why there is a push to consume heart-healthy fats higher in mono and polyunsaturated fats. Healthy fats may help lower LDL and, in some cases, raise HDL. Heart-healthy fats are found in oils such as olive and canola, avocados, and nuts such as almonds and walnuts. A diet high in fiber also tends to reduce cholesterol.

Regardless of whether or not your cholesterol levels are inherited, a healthy diet, exercise, and maintaining a healthy weight all may help contribute to normal cholesterol levels. Therapeutic Lifestyle Changes (TLC) is a program that addresses these three lifestyle factors. You can learn more about the TLC program and how it can help lower your cholesterol levels at http://www.nhlbi.nih.gov/files/docs/public/heart/chol_tlc.pdf.

High cholesterol has no signs and symptoms, so many people are unaware that they have it. Everyone over the age of 20 should have their cholesterol checked at least every five years, unless specified differently by a doctor.

If you're going to take one thing away from this article, please recognize National Cholesterol Education Month as a reminder to get your cholesterol screened, and talk to your doctor about your target numbers. You should know the "good" and the "bad" before it gets ugly!

Kimberly Young, MS, RDN, LD, is a Registered Dietitian at Panhandle Health District and a graduate of the University of Idaho Dietetic program.