Cholesterol is a steroid, a lipid, and an alcohol, found in the cell membranes of all body tissues, and transported in the blood plasma of all animals.
Most cholesterol is not dietary in origin, it is synthesized internally.
Cholesterol is present in higher concentrations in tissues which either produce more or have more densely-packed membranes, for example, the liver, spinal cord, brain and atheroma.
Cholesterol plays a central role in many biochemical processes, but is best known for the association of cardiovascular disease with various lipoprotein cholesterol transport patterns in the blood.
The name originates from the Greek chole- (bile) and stereos (solid), as researchers first identified cholesterol (C27H45OH) in solid form in gallstones.