Everyone encounters mental stress from day to day, from major life events to daily hassles. In this paper, both negative and positive effects of stress exercised on human physiological health is investigated. Effects of stress on the immune system, role as a cancer accelerator, pain inducer and cardiac disease initiator is researched upon. Although there are a number of researches supporting both positive and negative effects on human bodies, it is clear that stress can pose severe and even lethal effects on the human body when humans are exposed to stress for a long time.

Stress can have an adverse impact on one’s immune system. The immune system is the human body’s defence against harmful infections and diseases. With a weak immune system, a person is prone to flu, colds, allergies among other health disorders. (Kiecolt-Glaser et al, 1984) Kiecolt-Glaser concluded that students stressed about exams had a less effective immune system and hence were more prone to illness. Cortisol, the primary stress hormone is produced when a person is under stress. In short term such as when being chased by a wild animal, the stress response helps humans beings in survival. But if the cortisol remains in the bloodstream for a long duration of time, it begins to impair the immune system, hence being the cause of many infections and health problems. (Bickerstaff, 2010) Physical impairment by stress can also be explained by Hans Selye’s General Adaptation Syndrome model as discussed in