Coronary artery disease (CAD), also known as coronary heart disease, is now the leading cause of mortality in both men and women in the United States. It was reported by the Centers for Disease Control and Prevention that CAD caused nearly 616,000 deaths in 2011 and was responsible for 1 in 4 deaths in the United States that same year. 1 Coronary heart disease is a progressive disease in which the major arterial vessels that supply the heart become blocked and sclerotic due to the buildup of plaque in the inner walls of the artery through a process called atherosclerosis. 2 DKA ultimately leads to heart failure and myocardial infarction (MI). The heart is supplied with blood by its own vascular system through the circulation of the coronary artery. The left main coronary artery and the right coronary artery are the main branches that arise from the aorta and supply the left and right sides of the heart, respectively.3 Plaque buildup resulting from the disease causes a blockage of the blood supply through these major arteries, causing irreversible tissue damage. Three distinct layers of tissue make up the arterial walls: intima, media and adventitia. Each layer plays an important role in regulating blood flow throughout the body. The outermost layer of the arterial wall is the adventitia. This is composed of connective tissue cells and elastic components. The middle layer, or media, contains contractile smooth muscle tissue. This layer allows the lumen to dilate or narrow to facilitate blood flow during activity. Finally, the innermost layer is the intima, composed of a single layer of endothelial cells. Because the intima is one cell layer thick, it is vulnerable to injury from shear stress. Healthy endothelial cells he... in the center of the paper... tension. An increase in blood pressure makes the heart work harder to pump blood. This causes injury to the intimal layer of the artery, thus increasing the chances of atherosclerosis. 4Finally, physical inactivity also increases the likelihood of developing CAD. Being physically inactive significantly increases your chances of developing hypertension, obesity, and type II diabetes. Inactivity leads to poor autonomic control of the body. Therefore, the body's sympathetic drive increases, which significantly increases blood pressure possibly causing damage to the arterial walls. Poor insulin sensitivity also develops, which initiates the onset of type II diabetes. Ultimately, inactivity causes obesity. Obesity alone can lead to coronary heart disease because the heart has to work harder to pump blood throughout the body due to excess weight.