The immune system has been called our liquid nervous system. With our growing knowledge of the human body has come an increasing conviction that stress may be a factor in susceptibility to colds, flu, mononucleosis and other infectious illnesses. It appears that some of the hormones secreted in the presence of stress emotions impair or weaken the immune process by reducing the number of disease-fighting components such as lymphocytes (white cells) thus leaving us more vulnerable to infection. This may be one of the reasons why so many people die within a year or so of their spouse’s death. Recently there has been research into why some HIV positive patients develop full blown AIDS while others do not. One interesting finding is that patients with a more effective style of coping with stress seem to have stronger resistance as a result. It is now reasonable to hypothesize that stress emotions increase secretion of certain hormones. These hormones weaken the immune system and that weakness results in an increased likelihood of infectious illness.

Recent research indicates that brief time-limited stress that may be viewed as a challenge (e.g. passing an exam, good performance in sports, solving a difficult puzzle under pressure) may actually enhance the body’s immune response. However, chronic stress seems to reduce the effectiveness of the immune system and thus make the person more susceptible to diseases.