What is atherosclerosis and how does it occur?

Atherosclerosis is a build up of fat deposits in large and medium sized arteries. This causes narrowing of the blood vessels and can lead to cardiovascular disease. If a plaque ruptures it can cause occlusion of the blood vessel and lead to an event such as a heart attack.
Atherosclerosis occurs as a result of endothelium damage. This damage leads to an inflammatory response, white blood cells and LDLs accumulate at the site of injury and move into the damaged wall causing a cholesterol deposit or atheroma to build up. Calcium salts and fibrous tissue also accumulate, this decreases the elasticity of the artery and narrows the lumen. The narrowed artery increases the resistance against which the heart has to pump blood so causes high blood pressure.