(Source : « Mieux vivre en entreprise », P. Angel, P. Amar, MJ Gava, Brigitte Vaudolon, Dunod 2010)

The father of the modern stress, Selye (1907-1982), defines it "as a response of the body to adapt to all of the demands of its environment"; therefore stress is a natural reaction of adaptation, but potentially a source of disruption if it is too intense or frequent.

The Lazarus model (1984) defines stress as an imbalance between the demands of the environment and the resources of the individual. The diagnostic that the person makes of the situation, and the perception of the usable resources plays a key role here, regardless of the event.

Karaseck (1979) particularly insisted on three dimensions of health at work: the requirements of the tasks, the ability to make your own decision, and the social support of the colleagues and of the hierarchy.

Beyond the specificities of each model, the studies about stress at work involve three types of components: