According the General Adaptation Syndrome of Hans Selye (1907-1982), Alarm, Resistance and Exhaustion are three stages of the stress response.  Almost every system can be affected by stress. Symptoms are commonly caused from the physiological affects of catecholamines: heart palpitations, tachycardia, stomach upset, etc. (Copstead & Banasik, 2010).  As stress continues the person adapts.  When the ability to adapt exceeds the demands of the continued stress then the exhaustion ensues and the persons functioning fails.