Causes continued. High blood pressure is the next main cause of the development of atherosclerosis. Blood pressure is a measurement of two things, the first is the measurement of the pressure from your heart pushing the blood throughout the body. The second is the smaller blood vessels action of expansion or constriction, which influences the blood flow resistance. High blood pressure causes the arteries and vessels to become damaged, hard, and scarred over time. This allows the permutation of cholesterol through the endothelium, jump starting the plaque build up process. Smoking is also a cause of atherosclerosis because the toxins in the smoke encourage very high bad cholesterol levels and damage to the endothelium. As a person ages, the wear and tear on the arteries can also make them more susceptible to artery buildup of plaque.