Which type of cholesterol is commonly referred to as "bad" cholesterol?

Low density lipoprotein (LDL) is commonly referred to as "bad" cholesterol due to its role in transporting cholesterol to the cells. When there is an excess of LDL in the bloodstream, it can contribute to the buildup of plaque in the arteries, leading to atherosclerosis, which increases the risk of heart disease and stroke. In contrast, high density lipoprotein (HDL) is known as "good" cholesterol because it helps transport cholesterol away from the arteries and back to the liver for removal from the body, thus providing a protective effect against heart disease. Medium density lipoprotein and very low density lipoprotein do not have the same level of recognition or specific health implications associated as LDL and HDL do. Therefore, when discussing cardiovascular health, LDL is specifically highlighted for its potential negative effects, leading to its label as "bad" cholesterol.