General Adaptation Syndrome

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Stress has been a daily part of our lives since the beginning of mankind. And although our world has changed a lot through the centuries, the way our bodies respond to stress hasn’t. 

It’s almost impossible to avoid day-to-day stressors, but the good news is that we can manage our stress and keep its effects on our health to a minimum. But to do this, it’s important to first understand that stress has different stages known as the General Adaptation Syndrome.

What is General Adaptation Syndrome (GAS)?

General Adaptation Syndrome (GAS) is a term first coined by Austrian Austrian endocrinologist Hans Selye to describe a series of changes our bodies undergo during stressful situations. These changes include physical and mental symptoms such as headaches, higher blood pressure, exhaustion, sleeping problems, and more. 

While experimenting on lab rats in a 1936 McGill study, Selye observed that the rats showed physiological changes when exposed to various stressors. He recognized that, regardless of the type of stressor they were exposed to, the rats showed a similar series of symptoms after. 

By researching this process and developing the GAS theory, Selye became one of the pioneering minds in understanding what stress is, how it’s triggered, and what it does to our body.

General Adaptation Syndrome Stages

Selye observed that GAS occurs in three stages: alarm reaction, resistance, and exhaustion. According to his study, your body reacts differently to each stage. 

Alarm reaction stage

This is the first stage of GAS that occurs shortly after the stressful situation. This stage is also commonly known as our “fight-or-flight” response, wherein our body prepares to flee or fight to protect ourselves from perceived threats.

In this stage, your body alerts your brain about impending danger. In response, your brain starts releasing cortisol and adrenaline — known as stress hormones — which increase your heart rate, elevate your blood pressure, and give you a rush of energy.

During this stage, you may experience the following:

  • Increased heart rate
  • Increased breathing rate
  • Elevated blood pressure
  • Dilated pupils
  • Flushed or pale skin
  • Shaking

Resistance stage

Some time after your body goes into “fight-or-flight” mode, it tries to resist the changes brought about by the alarm reaction stage. 

It does this by lowering the cortisol released, which allows your heart rate and blood pressure to return to normal. Though your body is recovering, it’s still on high alert and prepared to switch back to the reaction stage if needed. 

During this stage, you may encounter the following symptoms:

  • Headaches
  • Stomach pains
  • Sleeping troubles
  • Melancholy
  • Irritability or moodiness
  • Difficulty in concentration

Once the stressful situation has passed, your bodily functions return to their pre-stress state. However, if the stressful situation persists for longer, your body tries to adapt by learning how to cope with higher stress levels. 

A prolonged resistance stage (chronic stress) quickly leads to the exhaustion stage.

Exhaustion stage

After the body has used all of its resources to undo the bodily changes, it will enter the exhaustion stage. 

In this stage, even if the stressful situation persists, your body won’t have enough energy to expend to address it. This leads to the familiar feeling of fatigue or burnout.

The longer and more often your body experiences the exhaustion stage, the more you’re prone to developing various health problems such as a weakened immune system, insomnia, anxiety, body pains, and more. It can also contribute to the development of major illnesses, such as obesity, heart disease, and more.

Triggers of General Adaptation Syndrome

Many things can trigger stress, which leads to the proliferation of general adaptation syndrome. These include:

  • Death of a loved one
  • Relationship problems
  • Heavy workloads
  • Problems at work or school
  • Major accidents
  • Sudden changes in your life or environment

Negative stressors aren’t the only thing that can trigger GAS. Positive stressors can also trigger it, albeit in a beneficial way. Here are some examples of positive stressors:

  • Winning a competition
  • Going on vacation
  • Riding a thrilling park ride
  • Going to a concert

Still, too much of something can be bad. An overabundance of positive stressors may lead to negative effects.


Despite the name, GAS is not a medical condition that can be diagnosed. It simply refers to a pattern of physiological symptoms we experience under stress. 

However, it’s important to recognize that GAS can significantly negatively impact your physical and mental well-being. And so, if you feel like the stress negatively impacts your day-to-day activities, it’s essential to get the right help from professionals. 

A licensed mental health professional, such as a psychologist, may help you find ways to manage your stress and suggest lifestyle changes to improve your health. 

For any physical ailments you may be feeling as a result of stress, seek help from the right health professional (a cardiologist for heart problems, a neurologist for sleep problems, a gastroenterologist for digestive issues, etc.).


It’s important to recognize the risks of being repeatedly exposed to stress or GAS, as it can have long-term negative impacts on your physical and mental health. Such impacts include:

  • Development of major illnesses and disorders
  • Weakened immune system
  • Decrease in stress tolerance
  • Constant burnout or fatigue
  • Depression
  • Anxiety

Managing General Adaptation Syndrome

Proper stress management is the key to preventing your body from physical and mental burnout during the exhaustion stage. Fortunately, there are many ways to do this, and here are a few:

  • Recognizing your triggers: The most straightforward way to deal with stress is to cut off its roots. You can do this by addressing the trigger head-on (aiming to resolve it) or simply avoiding it altogether.
  • Regular exercise: Studies say that exercise offers physical benefits and can significantly lower stress levels. Regular gym visits are good, but even something as simple as a stroll around the park or neighborhood will do. 
  • Breathing exercises: As simple as it sounds, breathing exercises are one of the most effective techniques to manage stress. The trick is to breathe deeply, which sends a signal to your brain telling it to relax and relieve stress.
  • Practicing mindfulness: Numerous studies show that mindfulness meditation has a huge impact on your stress levels and overall health. It’s a popular stress management technique as it doesn’t require any special equipment and can be done anywhere, any time.


In this busy and stimulus-filled world we live in, stress is practically unavoidable. That’s why we need to learn proper stress management to avoid developing health complications.

People cope with stress in different ways, so it’s important to recognize our stressors and perform the appropriate stress management techniques to regulate our stress levels and maintain a healthy physical and mental well-being.


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Stress Won’t Go Away? Maybe You Are Suffering from Chronic Stress. (2022).