General Adoption Syndrome (G.A.S.)

• General Adaptation Syndrome (GAS) is a three‑stage pattern of the body’s physical response to stress, proposed by Hans Selye.​
• It explains how the body reacts from the first experience of a stressor till either recovery or breakdown.
• GAS is mainly controlled by the sympathetic nervous system and the endocrine system (“fight or flight” response).

• When a person faces a stressful or threatening situation, the body automatically prepares to deal with it.
• This fixed pattern of physiological changes under stress is called General Adaptation Syndrome.
• GAS helps to explain how stress can gradually lead to physical illness if it continues for a long time (chronic stress).

1. Alarm Stage

• This is the first and immediate reaction to a stressor.
• The sympathetic nervous system is activated, and the body goes into fight‑or‑flight mode.

Main bodily changes

• Heart rate increases.
• Breathing becomes faster.
• Blood pressure rises.
• Stress hormones (such as adrenaline and cortisol) are released in high amounts.

This stage prepares the body for immediate action.

2. Resistance Stage

• If the stressor continues beyond the alarm stage, the body enters the resistance stage.
• Arousal is still higher than normal but lower than in the alarm stage.

Main bodily and behavioural features

• The body’s resources are used to cope with or resist the stressor.
• The person focuses on dealing with the stressor and pays less attention to other stimuli.
• Physiological arousal remains moderately high, and the person’s tolerance to the original stressor increases.

This stage can be maintained for some time as long as the body has enough resources.

3. Exhaustion Stage

• If the stressor continues for too long and the person is unable to overcome it, the body’s resources become depleted.
• At this point, the individual enters the exhaustion stage.

Main outcomes

• The person can no longer resist the stressor effectively.
• Feelings of tiredness, helplessness, and failure may appear.
• The risk of physical illness increases, such as high blood pressure, heart problems, or other stress‑related disorders.
• The severity of illness depends on the intensity and duration of the stress.

Chronic, long‑term stress is especially harmful because it weakens the body’s resistance.

• GAS depends on how the person perceives the situation.
• Stress is experienced only when an event is perceived as a threat.
• Uncontrollable stressors (where the person feels no control) usually have more harmful effects on the body than controllable stressors.
• When a person believes that the stressor can be controlled or managed, the impact of stress is reduced, and coping is better.

• People who are already depressed or frustrated are more vulnerable to the harmful effects of stressors.
• Social and emotional support from family, friends, and others strengthens coping and reduces the negative effects of stress.
• Optimistic, relaxed, and Type B personality individuals are generally less affected by stressors compared to tense, impatient individuals.

Hans Selye’s model leads to two key conclusions:

• GAS provides a clear framework for understanding how the body responds physiologically to stressful events through three stages (alarm, resistance, exhaustion).
• It explains the relationship between stress and illness: Long‑term (chronic) stress lowers the body’s resistance to disease and increases the risk of physical and psychological health problems.

• GAS: Three‑stage bodily response to stress (Alarm → Resistance → Exhaustion).
• Alarm: Immediate fight‑or‑flight reaction with very high physiological arousal.
• Resistance: Continued, moderate‑high arousal as the body attempts to cope and adapt.
• Exhaustion: Resources are depleted; the person’s resistance drops and illness risk rises.
• Perception of threat, controllability, personality type, and social support all influence how strongly stress affects health.