Cholesterol is a steroid lipid, 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.
It 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 in solid form in gallstones.
Heart disease is caused by narrowing of the coronary arteries that feed the heart. Like any muscle, the heart needs a constant supply of oxygen and nutrients, which are carried to it by the blood in the coronary arteries.
When the coronary arteries become narrowed or clogged by cholesterol and fat deposits– a process called atherosclerosis— and cannot supply enough blood to the heart, the result is coronary heart disease (CHD). If not enough oxygen-carrying blood reaches the heart, you may experience chest pain called angina.
If the blood supply to a portion of the heart is completely cut off by total blockage of a coronary artery, the result is a heart attack. This is usually due to a sudden closure from a blood clot forming on top of a previous narrowing.