GO away bad cholesterol - Why do we not want LDL?

Lipoproteins: Lipid (fat) + Protein, whose function is to transport lipids (fats) (such as triacylglycerol) around the body in the blood.
There are 5 major groups 

Lipoprotein structure (chylomicron)
ApoA, ApoB, ApoC, ApoE (apolipoproteins); T(triacylglycerol); C (cholesterol); green (phospholipids)
Picture - Wikipedia


Their size varies - small to Big  (chylomicrons, VLDL, IDL, LDL, & HDL)


Low-density lipoprotein (LDL)  enable transport of multiple different fat molecules, including cholesterol, within the water around cells and within the water-based bloodstream. 


Higher levels of BAD cholesterol AKA type-B LDL particles (as opposed to type-A LDL particles) increase health problems and cardiovascular disease


Blood tests typically report LDL-C - This is a calculated measurement
Direct LDL-C measurement using Nuclear magnetic resonance spectroscopy is superior and more accurate


LDL subtype patterns

LDL particles vary in size and density. Pattern that has more small dense LDL particles, called Pattern B, equates to a higher risk factor for coronary heart disease (CHD) than does a pattern with more of the larger and less dense LDL particles (Pattern A). This is because the smaller particles are more easily able to penetrate the endothelium. 
Pattern I, for intermediate, indicates that most LDL particles are very close in size to the normal gaps in tthe endothelium.
There is also relation ship between higher triglyceride levels and higher levels of smaller, denser LDL particles and alternately lower triglyceride levels and higher levels of the larger, less dense LDL