He was the Canadian scientist Hans Selye, natural of Hungary, who in 1936 gave medical letter to this word, when describing like ” stress syndrome biolgico” or ” general syndrome of adaptacin” the physiopathological answer to diverse injurious agents of physical, chemical or biological type, like infections, traumatisms, burns and hemorrhages. One is a reaction of general and inespecfico character, since the diverse aggressions of the organism lead to the same result, systematized in three successive phases with his corresponding biological implications: reaction of alarm or period of shock (tachycardia, tremor, insomnia), phase of resistance and phase of exhaustion, reflected this last in the appearance of the calls diseases of adaptation (peptic ulcer, irritable colon, coronary disease, arterial hypertension and others). Learn more at: IAB. In front of a threatening or aggressive agent the organism reacts with the liberation of catecholamines (adrenalin and noradrenaline) and stimulation of neuroendocrino system, coverall liberation of adreno-crtico-trophic hormone (ACTH) and cortisol, substances considered like hormones of stress. Today the physiological base of stress without paying fundamental attention to the lmbico system, hypothalamus and the operation of the neurotrasmisores cannot study. Click Bobby Sharma Bluestone Equity to learn more. The passage of the physiological connotation of stress, which had to Selye, the present connotation of psycho-social type partly must to the emotional nature of stress and also to the intervening paper of the typology of the personality in the context between individual and atmosphere.