General Adaptation Syndrome (GAS) – The Three Stages of Stress Response

In 1950, Hans Selye gave us the General Adaptation Syndrome (GAS), also known as ‘The Three Stages of Stress’.

GAS is the three-stage process that describes the physiological changes the body goes through when in stress response. So, today, when statistics on stress-related illnesses, workplace stressors, anxiety and depression are skyrocketing, we need to pay more attention to what we have known since 1950; specifically, that when we are responding to stressors, our bodies can pass through three specific stages of stress response. Understanding these different stages and how they relate to each other can help us avoid burnout.

Stages of our stress response:

1) Alarm stage

2) Resistance

3) Exhaustion

Whether we pass through all three stages will depend entirely on the events, situation or people that triggered our stress response.

Alarm Stage – Acute Stress Response: The Alarm Stage refers to the body’s initial response to stressors when the sympathetic nervous system is activated by several hormones including adrenaline and nor-adrenaline. These hormones not only trigger a plethora of physical changes including heart rate, breathing rate, blood pressure, but also decrease functionality of important systems including our digestive and immune systems. These physiological activations put the body on high alert until we have resolved the stressor. This alarm stage of stress response is short-term, and the stressor should be resolved.

Resistance Stage – Chronic Stress Response: The resistance stage is when the body tries to repair itself after the initial shock of the stressor. After we have coped with a stressor and have signalled the brain, we are safe, the brain automatically triggers the neurotransmitter GABA to stop the flow of adrenaline and nor-adrenalin and initiates the recovery stage. It keeps the body on high alert while repairing it until hormone levels, breathing rate, heart rate and blood pressure decrease, and the body is restored to normal rest state.

However, when a stressor continues and the brain cannot trigger GABA, it initiates the second line of defence by adding several new hormones to the list already flooding the bloodstream, including the steroid hormone, cortisol. Cortisol is the hormone doing all the damage in chronic stress response, causing the immune, digestive, sleep and reproductive systems to be decreased while increasing the cardiovascular system; heart rate, breathing and blood pressure are severely increased. The body now must work very hard to pump all these hormones through the bloodstream and maintain all these physical changes until the stressor is resolved. The body and mind are now in attack mode fighting the stressor.

Physical and mental indications of the resistance stage: When we don’t get relief from the alarm stage, we slowly start feeling a reduction in energy levels. Because we still want to fight the stressor, we feel exasperated, get very impatient with trivial matters, start getting less sleep and generally find our resistance to physical and psychological illnesses getting weaker because our immune system is weakening. The body now reacts by sending signs and symptoms of high hormone levels that lead to distinct changes in our physical and mental behavioural patterns. Some signs and symptoms may be:

  • Changes in appetite, stomach problems, lack of energy and motivation
  • Feeling of fear, anger, worry, frustration, irritability
  • Headaches, pain throughout the body, skin irritations
  • Problems with sleep; issues with falling and staying asleep
  • Trouble with concentrating, memory recall, details, focusing and decision making
  • Weariness, anxiousness, depression
  • Overindulgence with smoking, taking drugs, alcohol and eating difficulties

Long-term chronic stress response will lead to the exhaustion stage

Exhaustion Stage – Burnout: This stage is the result of prolonged chronic stress response that drains physical, emotional, and mental resources to the point where the body and mind no longer have the strength to fight the stressors. The body and mind are now worn out. The exhaustion stage results in long-term absenteeism from work and home responsibilities and possible physical and mental breakdown. Recovery can take a long time. This does not happen without warning; the body and mind have been begging for help and attention, sending signs and symptoms they were in trouble, but all was ignored. At this stage, finding a qualified stress and burnout counsellor is probably a good idea.

Physical and mental indications of exhaustion: When we still cannot or will not resolve our stressors, the resistance stage of stress response, exhaustion/burnout settles in. We are now drained of all physical and mental energy. We do not even have the desire to work or play. The exhaustion/burnout stage leads to:

  • All of the above-mentioned physical and psychological issues, plus loss of mental equilibrium with possible extreme psychological complications
  • Overwhelming fatigue
  • Depression
  • Anxiety
  • Decreased or non-existent stress response; no motivation
  • Decreased immune activity; illnesses are more frequent and last longer
  • And more ….

GAS can occur with any type of real or perceived physical, emotional, social or psychological stressors. For example:

  • Job loss
  • Workplace stressors
  • Health issues
  • Financial troubles
  • Family breakdown
  • Relationship problems and breakdowns
  • A death of a loved one
  • Trauma
  • And much more….

Signs that you are in the exhaustion stage include:

  • Fatigue
  • Burnout
  • Cannot tolerate any kind of stress

While stress is unpleasant, the upside is that GAS improves how our bodies respond to stressors, particularly in the alarm stage. The fight-or-flight response that occurs in the alarm stage is for our protection. A higher hormone level during this stage benefits us. It gives us more energy and improves our concentration, so we can focus on the stressor and cope to resolve it.


When stress is short-term, the alarm stage isn’t harmful. However, this isn’t the case with chronic stress; the longer we deal with a chronic stressor, the more harmful it is to our physical and psychological health and wellbeing. We also don’t want to remain in the resistance stage for too long, at risk of entering the exhaustion/burnout stage.

Stressors = hormones = physical and psychological illness. You can easily reduce hormone levels by de-stressing several times a day.

 By Joan Maycock

Joan Maycock MSc Health Psychologist. Stress and Burnout Specialist. Stress and Burnout Programme Developer. Mediator, Consultant, Trainer. Providing one on one stress and burnout sessions and stress and burnout educational workshops designed to get everyone thinking about reducing, preventing and managing stress and burnout.

915 793 592 | [email protected]