LDL cholesterol is an unhealthy form of cholesterol that collects in the walls of blood vessels and causes blockages of atherosclerosis. LDL particles are microscopic blobs that are less dense than other kinds of cholesterol, states WebMD.
Cholesterol cannot dissolve in the blood, and as proteins carry LDL throughout the body to be digested LDL deposits in artery walls. White blood cells attempt to swallow and digest the LDL, and this process results in the LDL being converted to a toxic form, and more white blood cells migrate to the area in an attempt to repeat the process of digestion. Over time, this area becomes congested with the accumulated LDL and cells and creates a plaque that blocks the flow of the artery. This may result in a sudden rupture of the plaque's surface, and a blood clot can form and lead to a heart attack, reports WebMD.