Scientists have shown that anger, anxiety, and depression not only affect the functioning of the heart, but also increase the risk for heart disease. Stroke and heart attacks are the end products of progressive damage to blood vessels supplying the heart and brain, a process called atherosclerosis. Atherosclerosis progresses when there are high levels of chemicals in the body called pro-inflammatory cytokines. It is thought that persisting stress increases the risk for atherosclerosis and cardiovascular disease by evoking negative emotions that, in turn, raise the levels of pro-inflammatory chemicals in the body.