Atherosclerosis, the most common part of hardening of the arteries, is characterized by the presence of cholesterol-rich arterial thickenings (atheromas).  This progressive  disease  begins  with  the  intracellular  deposition  of  lipids,  mainly cholesterol  esters, in the smooth  muscle cells of the arterial wall. These lesions become calcified plaques, fibrous which narrow and can eventually block the arteries. The Blood clots are also more likely to happen that may stop the blood flow and deprive the tissues of oxygen.