Which lipoprotein is considered "bad cholesterol" due to its association with heart disease?

Low-density lipoprotein (LDL) is referred to as "bad cholesterol" because its elevated levels are closely linked to an increased risk of cardiovascular diseases. LDL carries cholesterol from the liver to the cells, and when there is an excess of LDL in the bloodstream, it can lead to the buildup of cholesterol in the arterial walls, forming plaques. This process, known as atherosclerosis, narrows the arteries and can result in serious conditions such as heart attacks and strokes.

In contrast, high-density lipoprotein (HDL) is often considered "good cholesterol" since it helps transport cholesterol away from the arteries and back to the liver for excretion or reuse. Very-low-density lipoprotein (VLDL), while also associated with lipoprotein transport, is not typically labeled as "bad cholesterol" in the same sense as LDL. Intermediate-density lipoprotein (IDL) falls somewhere between LDL and VLDL in terms of density and is less commonly discussed regarding cardiovascular risk. Thus, the specific designation of LDL as "bad cholesterol" is well-established in cardiovascular health discussions.