Medical correspondent Dr. Emily Senay explained on The Early Show that cholesterol is essential to life - it's found in cell walls and hormones.
The liver manufactures 80 percent of the body's cholesterol. The other 20 percent comes from sources outside the body. Senay says too much cholesterol from diet can build up over time in the cardiovascular system, causing atherosclerosis (hardening of the arteries).
There are two types of cholesterol. Low-Density Lipoprotein (LDL) cholesterol is commonly known as "bad" cholesterol. It builds up on the walls of the arteries and causes problems over time.
High-density Lipoprotein (HDL) cholesterol is known as the "good" cholesterol. It helps move the bad cholesterol through the body's system to get rid of excess amounts. With enough "good" cholesterol, the "bad" cholesterol doesn't get a chance to build up.
Doctors recommend a complete screening for LDL, HDL and total cholesterol at the age of 20 and every five years thereafter.
Your total cholesterol should be less than 200. Levels of "good" cholesterol should be above 40. Levels of "bad" cholesterol should be less than 130, or less than 100 if you already have heart disease.
Those with a total cholesterol below 200 could still be at risk, she says, because a "bad" cholesterol may be high and "good" cholesterol may be too low.
For instance, Senay explains, two people may have the same total cholesterol count, such as 195, but very different health prognosis. A good profile would be somebody who has a high "good" cholesterol number of 100 and a low "bad" cholesterol level of 95. A bad profile, Senay says, would be if the "good" cholesterol is low at 25, and the "bad" cholesterol is at 170.
The medical community is learning more about how lifestyle choices are important in the way they affect levels of "good" cholesterol as well as "bad."
Senay says maintaining an ideal weight, proper nutrition and regular exercise are now known to boost high cholesterol, as well as lower "bad" cholesterol. Certain foods such as soy, whole grain oats or fish containing omega-3 fatty acids can lower cholesterol.
Quitting smoking can help boost "good" cholesterol, too. And, certain drugs can help in conjunction with lifestyle choices to lower "bad" cholesterol.