Comprendre le stress, le syndrome général d'adaptation

Understanding stress, general adaptation syndrome

Aug 29, 2022

It was Doctor Hans SELYE who introduced the concept of stress into medicine at the beginning of the 20th century , in his work Stress of life . He describes stress as a defensive alarm response emanating from a threatened organism . The word stress is an English word with Latin roots: “ stringere ” and “ stressus ” which means: “ narrow, tight, or pressed ”.

Stress describes the sensations that we all recognize and which correspond to an exceptional event or situation , or in any case to something which is not usual and which can be destabilizing. Stress is a set of constraints that will provoke a reaction in the body by inducing a General Adaptation Syndrome .

What is General Adaptation Syndrome?

The General Adaptation Syndrome is made up of 3 phases:

Phase 1 : The alarm reaction

It is the immediate reaction to stress: flee or attack. At this stage the adaptation capacities are mobilized. Hormones called “catecholamines” are released by the body. They cause an increase in heart rate, blood pressure, body temperature and cause vasodilation of muscle vessels. The goal is to deliver oxygen to the brain, heart and muscles to prepare the body for action.

Phase 2 : Resistance

After the alarm reaction, a second neuro-hormonal axis is activated , preparing the body for energy expenditure. New hormones are secreted: glucocorticoids . These hormones increase blood sugar levels to provide energy to the brain, heart and muscles. Glucocorticoids can slow down their own secretion by feedback: the quantity of hormones released into the blood is detected by receptors in the central nervous system which regulates it.

Phase 3 : Exhaustion

Exhaustion is the consequence of prolonged exposure to stress . The body's resistance decreases more and more before finally giving in. The power of adaptation of a living being is always limited. The body is overwhelmed and stress then becomes chronic. To cope with the situation, the body produces more and more hormones and becomes exhausted.

The “stressors”

Anything that causes the production of stress hormones is by definition a “ stressor .” They can be grouped into 3 categories: physical, psychological, and absolute .

Physical stressors : Cause tension or strain on our bodies, such as very cold or very hot temperatures, injuries, pain or illness.

Psychological stressors: These are events, situations, individuals, or anything that we interpret as negative or dangerous according to our own singularity.

Absolute stressors : These are universal stressors such as an earthquake, an attack, etc. Whether physical, psychological or absolute, stressors always cause hormone secretion.

For a situation to be stressful , there must be one or more of the following elements that characterize it:

  • Control : The individual has little or no control over a given situation
  • Unpredictability : A totally unexpected event occurs
  • New : A situation that has never been experienced before arises
  • Ego threatened : Competence and ego put to the test. Questioning of abilities by a third party.

All of these situations cause the release of stress hormones, as does the simple act of anticipating these situations.

Woman stressed in front of an alarm clock, a computer, a telephone, a cup and an hourglass

What is the anticipation effect?

The ability to anticipate can be a mediator of stress to the extent that it makes the individual capable of imagining and projecting oneself into situations that are potentially dangerous or that arouse a negative feeling. This anticipation can have a positive effect if it provokes an evaluation of the situation, so as to put in place strategies aimed at “ coping and taking action. On the contrary, it can have a negative effect when it takes the form of incessant ruminations and leads to procrastination. We then speak of anxious anticipation which is practically always present when the anxiety is pathological.

The power of the alarm reaction and chemical mediators

Assessment of the situation Response to the situation Chemical mediator
  • I can make it happen.
  • I am in control of the situation.
  • I pass.
  • Noradrenaline
  • Adrenaline
  • It is too much for me.
  • Am I capable?
  • I'm afraid of failing.
  • Adrenaline
  • Cortisol
  • Noradrenaline
  • I feel powerless).
  • I have no control over the situation.
  • I failed.
  • Cortisol
  • Adrenaline

Some points on stress hormones

Noradrenaline: It is a neurotransmitter. It is one of the precursors of adrenaline. Noradrenaline also acts as a hormone when it is released into the bloodstream from the adrenal medulla glands, often during stress or intense physical exertion. It thus promotes excitement, vigilance, learning or sleep.

Adrenaline: It has a vasoconstrictor action through significant alpha-adrenergic stimulation. It helps combat vasodilation and excess vascular permeability responsible for intravascular fluid loss and hypotension, the main pharmacotoxic symptoms of anaphylactic shock.

Cortisol : In the event of stress, cortisol levels rise massively in order to give the body the means to better manage this stress: maintaining glucose to the brain for example. However, it limits responses to inflammation or infections and brings down the immune system. In the event of chronic stress, cortisol levels remain high and can lead to disorders.

Testosterone : Testosterone is a male hormone secreted by the adrenal glands in men and women, but in greater quantities in men. High levels of cortisol appear to moderate the influence of testosterone, which is linked to aggressive and competitive behavior.

So good or bad stress?

Scientifically, and according to the National Institute for Research and Safety (INRS), there is neither good nor bad stress , but a phenomenon of adaptation of the body made necessary by the environment.

However, we can differentiate the state of acute stress from the state of chronic stress which will often have consequences on health.

The state of acute stress corresponds to our body's reactions when we face a threat or a one-off issue such as speaking in public, an urgent submission of files or even during a change of position at work. When the stressful situation ends, the symptoms also stop.

Chronic stress is our body's response to a stressful situation that continues over time. This is the case when every day at work we feel overwhelmed by the workload that has been asked of us. We consider that our resources are insufficient to cope. This state of chronic stress can have consequences on our mental and physical health.

Health consequences

All organs can be affected by prolonged hormonal imbalances : hypertension, heart attack, arthritis, ulcer, stroke, headaches, back pain, insomnia, irritability, dermatological, gynecological disorders, etc. The list is long. The psyche is also affected and in already weakened people, a state of chronic stress can lead to chronic and pathological anxiety , as well as depression . It can also cause behavioral disorders such as smoking, alcoholism, drug addiction or even lead to medication abuse.

Conclusion :

Widely used today, “stress” is a recurring term used to explain many of our physiological and psychological disorders resulting from adaptability disorders. If the beneficial aspect of stress is to be preserved, it is essential to put in place strategies to avoid its deleterious effects. Many treatments have proven their effectiveness, here are a few examples:
  • Drug treatment prescribed by a psychiatrist

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