About 10m working days a year are lost to stress. In our age of austerity, zero-hours working and weakened unions, has stress – a term only invented in the 1950s – become a shorthand for more complex problems?In 1925 a student at the Charles University medical school in Prague sat through his first lecture in the science of diagnosis, taking careful notes about how to examine a patient, and was struck by an observation that profoundly changed the history of modern medicine.