Cholesterol is stored in the liver. Because all cells use cholesterol, it needs to be transported from the liver through the bloodstream to all the body tissues. LDL cholesterol is basically a protein/cholesterol shuttle that ferries cholesterol from the liver to the tissues via the blood. The more cholesterol and saturated fats you consume, the more will be stored in your liver and sent out as LDL.  The higher the levels of this “bad” cholesterol, the longer it stays in the bloodstream and the more likely it is to stick to the walls of arteries and become a permanent plaque which can lead to atherosclerosis. This causes narrowing of the arteries and may lead to cardiovascular disease.  

HDL cholesterol is called the “good” cholesterol because it is a protein/cholesterol shuttle that scavenges up excess cholesterol from the tissues and returns it to the liver. It is short lived in the bloodstream and does not cause narrowing of the arteries. In general, increasing your HDL cholesterol levels is protective against cardiovascular disease.

A host of factors are involved in causing high cholesterol levels (see the risk factors that follow).