Cholesterol builds up silently, slowly choking off blood supply to your heart and brain. Get your cholesterol checked.

You see TV commercials, ads in magazines, and pamphlets lining your doctor’s office walls – all touting the dangers of high cholesterol. But you feel healthy and have never worried about your cholesterol or heart problems. So, why do you need to have a test?

What is cholesterol and how does it affect me?
Cholesterol is a fat-like substance that your body needs to function. Your body makes some cholesterol because it is needed to form cell membranes, some hormones and bile acids (which digest fat), for example. But people consume extra through foods, especially animal foods like meats, dairy products, and processed foods with trans fats.

When there is too much cholesterol in your blood, it can build up on the inside walls of your arteries. Over time the buildup, called plaque, can narrow the space for blood to flow through. This can happen in the arteries everywhere in the body. It is most dangerous, though, in the arteries that feed the heart, brain, and other vital organs.

When plaque buildup narrows the coronary arteries, which supply oxygen-rich blood to the heart, it can cause chest pain, shortness of breath and other symptoms of coronary heart disease. If a clot forms on the plaque, it can block the blood flow to the heart muscle, causing a heart attack. If a clot blocks the flow of blood to the brain, it can cause a stroke.

The higher your levels, the greater your risk of heart disease and stroke. Given that heart disease is a top killer of men and women in the U.S., this is not a risk that you should ignore. But, eating a heart-healthy diet, being physically active and losing weight are things everyone can do to help lower their levels and their risks.

What’s being measured when your cholesterol is checked? Why is some referred to as “good,” while other as “bad”?

Your doctor may order tests to check your blood levels. Because it can’t dissolve in the blood (it’s not water-soluble), it doesn’t circulate by itself. Instead, it travels through the bloodstream linked to “carriers” called lipoproteins.

There are three different types of lipoproteins. The two that are most important to remember in terms of your possible risk of heart disease are high-density (HDL) and low-density lipoproteins (LDL).

LDL is carried on low-density lipoproteins (the “bad” cholesterol). Higher levels of LDL are linked to an increased risk for heart disease.
HDL is linked to high-density lipoproteins (the “good” cholesterol). If you have higher levels of HDL, you’re at lower risk for heart disease.

“Good” and “bad”
Experts believe that LDL is the main carrier of cholesterol to body tissues, and HDL carries cholesterol away from body tissues.

When you have a lot of LDL, there is more of a danger that too much may be deposited in artery walls. This may then damage the walls. The arteries may develop a fatty buildup called a plaque on the inside. This is called atherosclerosis, or “hardening of the arteries.”

When you have higher levels of HDL in your blood, it means that more high-density lipoproteins carry cholesterol away from arterial walls and to the liver. The liver then eliminates the cholesterol from the body by excreting it in the bile. Clearly, the more this happens, the less likely that plaque will accumulate in arterial walls and worsen the progression of atherosclerosis.

Why test?
Plaque can prevent adequate amounts of blood from flowing to the heart muscle. It is the most common cause of coronary heart disease and happens so slowly that you are not even aware of it. This plaque can rupture, forming a blood clot that leads to a heart attack or stroke. The higher your LDL, the greater your chance of heart attack or stroke. This is why screening is so important. Cholesterol can build up for many years before any symptoms develop. So, you can feel healthy and not realize you have high cholesterol.