Fight or Flight

Hans Selye researched the physiology of stress in the 1930's and believed that stress was 'the rate of wear and tear of the body'. He also believed that every individual had a certain amount of adaptive energy. Once it was used up it could not be replaced and burnout occurred.
He described the physiology of stress in his 'General Adaptive Syndrome' as moving through a predictable series of responses from alarm through resistance to exhaustion. Alarm is set off by the fight or flight response.

The "fight or flight response" is our body's primitive, automatic, inborn response that prepares the body to "fight" or "flee" from perceived attack, harm or threat to our survival. http://www.thebodysoulconnection.com/EducationCenter/fight.html

However, in today's world it will not be the tiger or bear that confronts but challenges and pressures of work and home relationships, situations and environment.
Walter Cannon identified the fight or flight response during his time at Harvard Medical School in the 1920's. The hypothalamus releases a chemical reaction that sends adrenaline, noradrenaline and cortisol into the bloodstream. Exposure to these chemicals in the system results in depletion of the immune system and inhibition of the manufacture of T-lymphocytes and Macrophages that are known as the killer T cells. This lowers our resistance to disease.
If the stressor persists for more than a brief time the body adapts to it and becomes resistant. The body systems return to normal but remain alert for the stressor. If the stressor is intense or long lasting then the body becomes exhausted and can no longer resist it. When the body is exhausted it becomes vulnerable to dysfunction and disease.
Hans Selye believed that almost any disease could be caused by chronic excessive emotional stress. Having a body primed for action but unable to act to use the hormones and chemicals circulating in readiness for action is detrimental to health. High blood pressure, high cholesterol, arteriosclerosis, heart attack and stroke may all be consequences of excessive and prolonged stress.