The Fight or Flight Response

What is the fight or flight response?

Any perceived possible threat to our survival, whether real or unreal sends information to the most primitive, reactive part of our brain which creates unavoidably noticeable signals to instinctively protect ourselves. This is known as ‘The Fight or Flight Response’.

Albeit a very normal physiological response to a danger or threat, the Fight or Flight response is a survival instinct that our ancient ancestors developed many years ago, enabling us to run away (take flight), fight, or freeze to be less visible when faced with danger. This response kept us alive because we needed to be on full alert from attacks by wild animals, warriors etc.

As the Fight or Flight Response is activated, a combination of nerve and hormonal signals prompts the adrenal glands, (located at the top of the kidneys), to release hormones, including adrenaline and cortisol.

Adrenaline increases the heart rate, blood pressure and energy supplies, whilst cortisol, which is our primary stress hormone, increases sugars (glucose) in the bloodstream. This enhances the brain’s use of glucose and slows down anything that is detrimental to the efficiency of the fight or flight system.

The Fight or Flight response was designed to deal with actual fear for our lives, but in today’s evolved world, is now predominantly triggered by feelings of, but not physical threats. However, as we continually engage our Fight or Flight response, we experience physical symptoms designed to temporarily change the way the body is functioning in order to enable rapid physical response. 


  • Heart beats faster
  • Circulation increases blood supply to our brain and muscles.
  • Blood pressure and body temperature rises.
  • We increase oxygen levels by breathing more (leading often to hyperventilating)
  • Pupils dilate so we have a greater awareness and vision.
  • Brain activity alters to think less but react more.
  • Arteries dilate.
  • Digestion slows down
  • The dump mechanism is instigated to make us lighter (this can include the need to use the toilet or vomit).

Understanding why the physical symptoms (above) kick in as they do will reassure you that your body is trying to protect you and not work against you.

Read more: Ways to reduce panic attacks and calm the fight or flight response.



Related Posts


What is TRUK TALK? TRUK TALK is a weekly online support group available for our members, where we prioritise creating a safe and confidential environment

The Most Common Cause of Anxiety

The Powerful Link Between Childhood Stress or Trauma and Anxiety Individuals who have experienced distressing or traumatic events during their formative years often have heightened

Navigating Anxiety in the Workplace

Understanding workplace anxiety In today’s fast-paced and demanding work environment, anxiety has become a prevalent challenge for many individuals. Balancing high expectations, tight deadlines, and

Cost of Living Anxiety

Are you struggling with financial difficulties? Struggling with financial issues can have a huge impact on your mental health and vice versa. If you are