general adaptation syndrome

psychology

Also known as: GAS

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Last updated

June 29, 2026

Quick Summary

The General Adaptation Syndrome (GAS) is a three-stage response to stress identified by endocrinologist Hans Selye.1

Alarm Reaction: When a stressor is first detected, the body activates the sympathetic nervous system and releases hormones like cortisol, epinephrine, and norepinephrine. This mobilizes the body for immediate action, increasing heart rate, blood pressure, and respiration.
Stage of Resistance: If the stressor persists, the body shifts to localized responses. Hormone levels return to near normal, but the body's ability to cope with the stressor remains high.
Stage of Exhaustion: If the stressor is not removed, the body's resources are depleted. Hormone levels rise again, and prolonged stress can lead to physical deterioration, maladjustment, and potentially death.

While GAS evolved to handle physical threats, it's also triggered by psychological stressors, which can sometimes be inappropriate and contribute to psychosomatic illnesses.2

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…a stressor is called the general adaptation syndrome and appears to have evolved primarily to deal with systemic stressors. As noted earlier, however, this same set of processes is also triggered by psychological stressors and is often inappropriate to the situation. For example, the stress of an important upcoming test…
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…a stressor is called the general adaptation syndrome and appears to have evolved primarily to deal with systemic stressors. As noted earlier, however, this same set of processes is also triggered by psychological stressors and is often inappropriate to the situation. For example, the stress of an important upcoming test…
Read More

Hans Selye
…a stress condition known as general adaptation syndrome (GAS). He first observed the symptoms of GAS after injecting ovarian extracts into laboratory rats, an experiment he performed with the intent of discovering a new hormone. Instead, however, he found that the extract stimulated the outer tissue of the adrenal glands…
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…a stress condition known as general adaptation syndrome (GAS). He first observed the symptoms of GAS after injecting ovarian extracts into laboratory rats, an experiment he performed with the intent of discovering a new hormone. Instead, however, he found that the extract stimulated the outer tissue of the adrenal glands…
Read More