Medscape: The Anxious History of Understanding Cortisol Came across this on Medscape today and since we've been having discussions on what "stress" is elsewhere on the forum--to say nothing of the many discussions on cortisol and ME/CFS over many years--it seemed a bit interesting to see how our understanding of cortisol emerged. It's rather depressing that our idea of what "stress" is have not progressed much from the ideas of a guy who kept dropping lab rats over half a century ago.