The Fight or Flight Response

The fight or flight response or the 'acute stress response' was first described by Walter Cannon in the 1920's.

The acute stress response is the body's way of mobilizing resources to fight or flee from the cause of stress.

  • Excess muscle tension
  • pounding heart and racing pulse
  • butterflies in the stomach
  • sweaty palms
  • rushed thoughts
  • rapid breathing.

These are all signs of stress that the fight or flight response has been activated.


This stress response was later known as the first stage of the general adaptation syndrome.

Understanding how the stress response affects health helps build motivation to take control of stress today.

What is the fight or flight response: The quick message to the brain

Imagine that you are strolling down a dark street and a shadow passes that gives you a fright.

In a split second the body sends a signal to the amygdala which activates the sympathetic nervous system and inhibits the parasympathetic nervous system.

Stress hormones adrenaline and cortisol are secreted into your bloodstream.

This triggers a number of stress symptoms which include:

  • increased heart rate
  • higher blood pressure as blood is shunted to large muscles
  • sweatying as the body turns on the cooling system in preparation to fight or flee
  • an increased breathing rate to move oxygen to the muscles
  • tightening of muscles in preparation to act.

Essentially the body mobilizes resources to 'fight or flee' from the threat.

What is the fight or flight response: The slower message to the brain

Following the activation of the acute stress response a slower signal is sent to the cerebral cortex.

The cerebral cortex appraises the situation.

Was the shadow that passed over me due to a mugger or due to the lamp-post?

If you appraise the situation as non-threatening then an all clear signal is sent to the brain.

If you appraise the situation as threatening then a threat signal is sent and the stress response increased.

The stress response is our body's primitive automatic response that prepares us to fight or flee from the perceived stressor.

This response is hard-wired into our brains.

The stress response has served an adaptive function throughout evolution.

The extra energy and alertness thanks to the boost of adrenaline helped the caveman to escape from the proverbial saber tooth tiger that was lurking in the woods.

But such a response may not be the most appropriate for modern day saber tooth tigers.

The biggest causes of stress include the job stress, overwhelming family responsibilities, persistent financial stress, a lack of job security, or feeling pressured by a lack of time.

Anything that annoys, frustrates, or scares us has the potential to activate the fight or flight response.

But we cannot flee. We cannot fight!

The stress response can be counterproductive for much of today's common stress causes.

Most of today's types of stress are emotional. They can occur on a daily basis which can mean that the stress response is constantly activated.

This chronic stress can lead to a number of emotional and physical effects of stress.

So how does stress affect health? Too much stress for too long can:

  • weaken the immune system and make you more susceptible to depression and anxiety disorders
  • lead to disorders of the autonomic nervous system that include irritable bowel syndrome, high blood pressure and stress headaches.

Protecting yourself from the fight or flight response

To protect yourself from the effects of stress it is important to know what your causes of stress are and understand your stress signature.

Download and fill out this stress diary today.

By recognizing the warning signs of stress you can put into place a number of strategies to protect you from the effects of stress. These include:

  • Practice relaxation techniques.

    Relaxation techniques activate the relaxation response. The relaxation response is the direct opposite of the fight or flight response and can protect you from the physical and emotional effects of stress.

  • Change the way that you view the stressor.

    A contemporary definition of stress highlights that the way that we perceive the stressful event is important.

    As the saying goes "when life gives you lemons, make lemonade".

    Thus cogntiive techniques that work on reframing problems is useful. These may include positive thinking skills or techniques to develop a positive mental attitude.

  • Exercise frequently.

    One of the symptoms of stress is excess muscle tension.

    Excessive is a great way to use-up excess muscle tension and stress byproducts. When you exercise you restore your body and mind to a more calm and relaxed state.

    This article on exercise and stress illustrates how exercise is a great stress buster.

Search here for more stress management techniques

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