How Emotions Impact Health

There's a physiological reason why emotions can impact health. Different parts of the brain are associated not only with specific emotions, but also with specific hormone patterns. The experience ("release") of certain hormones, then, is associated with different emotional responses, and those hormones affect health. As one example, we know that emotionally induced shifts in hormones can lead to chronic disease, such as high blood pressure. When a person is aggressive and anxious, too much norepinephrine and epinephrine are secreted, even at rest. The arteries thicken, and the excess hormones cause blood vessel muscles to constrict. The gradual rise in blood pressure can then result in hypertension, stroke, or heart failure.
Other studies have borne similar results. It has long been believed, for instance, that as many as 70 percent of all people who go to a gastrointestinal specialist have irritable bowel syndrome, a mixture of pain, diarrhea, constipation, nausea, and sometimes vomiting. Most are women, and most have some kind of an emotional problem. One-fourth of gastroenterology patients have major depression.
The symptoms of irritable bowel syndrome were seen as a physical expression of emotions caused by recent loss or ongoing stressful life situations.
-Information found from Mind/Body Health THe Effects of Attitudes, Emotions, and Relationships on page 20 by Keith J. Karren