(HealthDayNews) -- Most health-conscious people know that too much "bad" cholesterol can raise your risk of a heart attack, but lots of people may not realize what cholesterol is or what it does, the American Heart Association says.
Cholesterol is a waxy substance that stems from two sources: the liver and the animal-based foods we eat. While the body needs cholesterol to insulate nerves, make cell membranes, and produce hormones, the body makes enough on its own without dietary help.
When there is too much "bad" cholesterol in your blood, it combines with other substances to build up on the walls of your arteries. This buildup is called plaque, and it causes arteries to become narrow, slowing blood and oxygen flow to the heart.
If the blood supply to a portion of the heart is mostly or entirely cut off by a blockage, conditions are ripe for a heart attack.