I read this recently and felt it applied to me.....I've GOTTA START MEDITATING! Apparently when we become upset chemical changes occur. Stress hormones are released and then you become habituated to increased muscle tension, heart rate, and blood pressure. The stress hormone "catecholamine" (adrenaline-like hormone) is released during acute anger. When you experience chronic anger and frustration during the day, there is an excess of cortisol, a hormone that INCREASES agitation, and a decrease of serotonin, which calms you down. An excess of catecholamine can create anxiety, apprehension and fear. In addition, catecholamine speeds up the heart and can cause cardiac problems. An excess of cortisol leads to increased vigilance and a restless mind. You experience an exaggerated startle response, sounds appear louder, and lights seem brighter. During chronic anger and frustration, low levels of serotonin make it much harder to feel happy and fulfilled, which can lad to depression. Concurrently the endorphins that create a sense of joy literally dry up, resulting in poor relationships with people.