
Autopsy of stressed rats revealed three major, grossly visible changes: hyperemia and enlargement of the adrenals, atrophy of the thymus and lymph nodes as well as hemorrhagic gastric erosions/ulcers (the "stress triad"). His results in that short publication that contained no references or illustrations, were based on experiments in rats that were exposed to severe insults/ stressors, but his idea about a 'nonspecific bodily response' originated from his observations of sick patients whom he had seen as a medical student and young clinician.

The first scientific publication on 'general adaption syndrome', or as we know today 'biologic stress' has been published in Nature in 1936 by the 29-year old Hans Selye.
