What is Hypercholesterolemia?
{{no sources }} '''Hypercholesterolemia''' means that the [[cholesterol]] level is too high in the [[blood]]. ==Cholesterol== {{Main article|Cholesterol}} Cholesterol is a [[molecule]] in [[cell]]s. It is a type of [[lipid]] which is a [[fat]] or fat-like [[molecule]]. Cholesterol is a special type of lipid that is called a [[steroid]]. Steroids are lipids that have a special [[chemical]] [[structure]]. This structure is made of four rings of [[carbon]] [[atom]]s. Other steroids include [[hormone]] steroids like [[cortisol]], [[estrogen]], and [[testosterone]]. All steroid hormones are made from changing the basic chemical structure of cholesterol. When [[scientist]]s talk about making one molecule from changing simpler ones, they sometimes call it ''synthesis''. ==Jobs== Cholesterol does many important jobs in a cell. Cholesterol's main function is as a structural component of [[cell membranes]]. It is also the starting material for [[Bile|bile acid]]<nowiki/>s that are made by the [[liver]] and used to digest fats, and for steroid hormones. However, it is best known for something bad that it does. High levels of cholesterol can lead to [[atherosclerosis]]. This is an inflammatory disease of [[artery]] walls in which [[white blood cells]] invade the vessel wall and become engorged with cholesterol and other lipids. These areas can slowly close off a [[blood vessel]] or can suddenly rupture and trigger formation of a blood clot. ==Types== Not all cholesterol is bad. There are different kinds of cholesterol in the blood. Doctors often measure these different types to see if someone has hypercholesterolemia. HDL ([[high density lipoprotein]]) is sometimes called 'good cholesterol' because people with high levels of HDL cholesterol have ''less'' atherosclerosis. LDL ([[low density lipoprotein]]) is sometimes called 'bad cholesterol' because people with high levels of LDL cholesterol have more atherosclerosis. High blood levels of VLDL ([[very low density lipoprotein]]) also causes more atherosclerosis. Ho