What is stress?

History of stress

Close-up on …The General Adaptation Syndrome

In Hans Selye’s theory, General Adaptation Syndrome had three stages.

Stage 1 : Alarm reaction

This is the immediate reaction to a stressor. In the initial phase of stress, humans exhibit a "fight or flight" response. This stage takes energy away from other systems (e.g. immune system) increasing our vulnerability to illness.

Did you know?

Hans Selye pioneered the field of stress research and provided arguments that stress impacted health.


Stage 2 : Resistance

If alarm reactions continue, the body begins getting used to being stressed. But this adaptation is not good for your health, since energy is concentrated on stress reactions.

Stage 3 : Exhaustion

This is the final stage after long-term exposure to a stressor. The body's resistance to stress is gradually reduced and collapses as the immune system becomes ineffective. In Selye’s view, patients who experience long-term stress could succumb to heart attacks or severe infection due to their reduced resistance to illness.