Q. What are the so-called "good" and "bad" cholesterol?
Lipoproteins are complexes made of lipids (cholesterol and triglycerides) and proteins. The lipoproteins present different densities according to the relationship between their lipid and protein quantities since lipids are less dense than proteins. Low-density lipoproteins (LDL) are those with a low protein/lipid relation high-density lipoproteins (HDL) have a high protein/lipid relation another group is the very low-density lipoproteins (VLDL) with very low protein/lipid relation.
LDL is called as "bad cholesterol" because it transports cholesterol from the liver to the tissues and so induces the formation of atheroma plaques inside blood vessels, a condition called atherosclerosis do not confuse with arteriosclerosis that can lead to severe circulatory obstructions like acute myocardial infarction, thrombosis and cerebrovascular accidents. HDL is called as "good cholesterol" since it transports cholesterol from the tissues to the liver to be elevation of the HDL and eliminated with the bile blood level reduces the risk of atherosclerosis (VLDL transforms into LDL after losing triglycerides in the blood).