What is stress?

We all experience stress in our daily life, but what it is exactly and how does it affect us?

Definition of stress

We all think that we know what stress is. However, if we try to give a clear definition of it, most attempts will refer to workload or time pressure. But stress is much more than that. Even in the field of neuroscience, no precise definition has been found to date. There is nevertheless a general description that is widely accepted:

Stress is an adaptive response of our body to challenges, also called allostasis

Allostasis refers to the adaptive processes to maintain our internal balance in response to stressors. If stress is constantly present, and these processes are relentlessy requested, this can lead to damage, termed allostatic load. Over time, this load leads to irrevocable effects, identified as a state of allostatic overload. The body and brain are worn down and disorders occur.

What is stress?

Unlock the mysteries of stress

Is stress really negative? What happens in our body when stressed? And what about chronic stress? Can we counteract or prevent stress? Find out the answers to these questions and many more in this fun animated video.

History of stress

Hans Selye, an Austrian-Hungarian endocrinologist, is considered the pioneer of stress research. During an internship in a hospital while studying at the University of Montreal, he noticed that all patients, regardless of the reason for their hospitalization, looked sick. He coined the term stress as it is used today by introducing the concept of General Adaptation Syndrome. He defined stress as "the nonspecific response of the organism to any demand made upon it" and suggested that the General Adaptation Syndrome develops in three phases: the initial alarm response (fight or flight) aimed at restoring homeostasis (or internal equilibrium); the stage of resistance describing the adaptation of the organism to a sustained stressor; and the stage of exhaustion during which the organism's resistance is progressively reduced and the ability to resist disease is eliminated.

Many researchers later challenged Selye’s definition of stress. For them, stress cannot be a non-specific phenomenon, because in the same situations, everyone experiences the level of stress differently. However, they agreed that there must be common elements that stimulate the stress response. This led to the identification of what can be called the ingredients of the stress recipe: lack of control, unpredictability, novelty and threat to the ego.

Understand the terms
Learn more