Like fat, cholesterol isn't a bad thing. Every cell in your body contains some cholesterol, which is necessary for normal cell function and production of certain hormones. Your liver produces all the cholesterol you need, so it's not an essential nutrient you must get from food. The excess cholesterol circulating in your bloodstream is the problem. Eventually, it builds up on the walls of your arteries and can block blood flow. When the coronary or cerebral arteries are blocked, the result is heart attack or stroke.
The familiar initials LDL and HDL are two types of protein-encased packages called lipoproteins that ferry cholesterol around in your blood. The higher your LDL level, the more cholesterol circulating in your bloodstream. LDL drops cholesterol off where it's needed, but it also deposits excess cholesterol along your artery walls and in other tissues. That's why LDL is characterized as "bad."
The HDL lipoprotein package cleans up the excess cholesterol left by LDL and returns it to the liver. The more HDL you have, the more thorough the cleanup. Consequently, HDL is considered protective or "good." For women, a high triglyceride level may be a better predictor of heart disease than high LDL, and a low HDL level is especially dangerous.
People's response to dietary cholesterol varies. Some are very sensitive to it; others have only a minimal response. But cholesterol levels aren't determined by diet alone. Age, heredity, weight and weight distribution, as well as level of exercise have an impact, too.
Cholesterol is simply a lipid which is found in the cell membranes of all body tissues. It is a fact that most of the cholesterol is synthesized by the body and some has dietary origin. Cholesterol can simply be divided into good and bad cholesterol. “Bad cholesterol”, also called LDL (low density lipoprotein) can have harmful action in your body while “good cholesterol” often referred to HDL (high density lipoprotein) have beneficial actions.