Atherosclerosis is when arteries become blocked by cholesterol. High cholesterol is a factor of atherosclerosis. Over time cholesterol deposits build up in arteries and may cause a blockage of blood flow. Two predisposing factors for atherosclerosis are unhealthy eating and lifestyle. Unhealthy eating can bring on excess cholesterol in the body making the condition worse. a healthy lifestyle can help to remove cholesterol from the veins and arteries while an unhealthy lifestyle will create and optimal environment for cholesterol to build up. Atherosclerosis is the most common form of arteriosclerosis, which is basically thickening of artery walls. (Marieb & Hoehn, 2007) This can lead to hypertension or high blood pressure. Atherosclerosis can affect all arteries in the body, but mainly the coronary, carotid arteries, and the aorta. (Marieb & Hoehn, 2007)Half of the deaths in the western world are indirectly caused by atherosclerosis (Marieb & Hoehn, 2007), and although some factors are hereditary others are manageable. The disease is thought to progress in stages. (Marieb & Hoehn, 2007) The first stage is caused by damage to the endothelium. Many things can trigger this damage, but they all lead to the onset of atherosclerosis. Once this happens the body attempts to repair the injured tissues by transporting lipids in the blood. (Marieb & Hoehn, 2007) Unfortunately these cells become so engorged with lipids that they become foam cells. These foam cells accumulate and form fatty streaks, the first sign of atherosclerosis (Marieb & Hoehn, 2007). After this occurs, smooth muscle cells release collagen and other elastic fibers into the affected area which in turn thickens it. (Marieb & Hoehn, 2007) Plaque grows in the vein until it becomes unstable and eventually ruptures. Steps that can be taken to avoid or slow the progression of the disease would be to avoid smoking, exercise regularly, maintain weight, and to increase