Fight, Flight, Freeze, or Fawn: How We Respond to Threats

It is your turn to present in front of a big crowd. While out for a walk, a dog jumps onto your path and begins barking at you. You are driving down the highway, the car in front of you suddenly stops, and you slam the brakes.

These are examples that trigger the fight or flight response (also known as the acute stress response).

Fight or Flight Response

What is Fight or Flight?

The fight or flight response is the body’s natural physiological reaction to stressful, frightening, or dangerous events. It is activated by the perception of threat, quickly igniting the sympathetic nervous system and releasing hormones, preparing the body to face a threat or run to safety.

The term “fight-or-flight” is our engrained survival instinct and represents the options our ancient ancestors could choose when dealing with dangerous environments. Back then, when you faced a hungry saber-tooth tiger, you could only run or fight. Many of the high-arousal situations we face in the modern world are more psychological in nature (e.g., a job interview).

American physiologist Walter Cannon coined the term after realizing that an unconscious and automatic series of fast-acting reactions occurred inside the body to help assemble resources the body needs to manage threatening circumstances.

He also called it the acute stress response. To delve into the history, in Cannon’s (1915) book, Bodily changes in pain, hunger, fear, and rage, he noted that when a predator threatened an animal. For example, their bodies proceeded to release the hormones epinephrine and adrenaline, which triggered the fight or flight response.

Cannon remarked that this process happened unconsciously and automatically and served the function of helping the animal to defend itself in life-threatening situations by prepping the body to run or fight.

What Is Fight, Flight, or Freeze?

In the years since his research, physiologists and psychologists have developed and refined Cannon’s work, coming to a better understanding of how people react to threats.

Thus defining what is now called fight, flight, freeze, and fawn:

  • Fight: facing any perceived threat aggressively.
  • Flight: running away from danger.
  • Freeze: unable to move or act against a threat.
  • Fawn: immediately acting to try to please to avoid any conflict.

Again, when one feels threatened, the body rapidly responds to imminent danger. The underlying goal of springing into fight, flight, freeze, or fawn, is to decrease, end, or evade the danger to return to a state of calm and control.

How Does it Work?

You can possibly think of a time when you encountered the fight or flight or freeze or fawn trigger.

Whether it was a physical danger (finding a predatory animal like a snake on a nature walk) or a psychological danger (asking someone out on a date), you may start breathing faster, you can feel your heartbeat quicken, and your whole body becomes tense – ready to take action if necessary.

Let us get deeper into the science and anatomy of this response. The reaction begins in the amygdala, the section of your brain responsible for fear. The amygdala responds by transmitting signals to the hypothalamus, stimulating the autonomic nervous system (ANS).

The ANS comprises the sympathetic and the parasympathetic nervous systems – the fight or flight response is located in the former.

The sympathetic system activates and then stimulates the adrenal glands to trigger the release of catecholamines, including adrenaline and noradrenaline.

Acute stress response: Sympathomedullary Pathway

When a stressor is perceived, the hypothalamus activates the sympathetic branch of the autonomic nervous system. This, in turn, causes the adrenal medulla to release adrenaline into the bloodstream. This prepares the body for “fight or flight.”

The adrenaline and noradrenaline increase the heart rate and the breathing rate, the blood circulation is redirected to the skeletal muscles, and the digestion stops.

When the stressor subsides, the parasympathetic branch of the nervous system is activated, the heart and breathing rate decrease, digestion restarts, and all other functions return to normal.

The Physiological (Bodily) Stress Response

Here is a list of physiological signs and symptoms that can indicate whether or not the fight or flight or freeze or fawn response has kicked in:

  • Eyes: the pupils dilate. Allowing your eyes to absorb more light improves your eyesight so that more attention can be dedicated to danger. You might notice a “tunnel vision” or realize that your vision becomes “sharper.”
  • Ears: the same concept for the eyes applies to the ears. You will notice that your ears essentially “perk up,” and your hearing can become “sharper.”
  • Heart: heart rate increases, and there is a dilation of coronary blood vessels. A faster heart can feed more blood, oxygen, and energy into the body, enhancing your power to run away or fight.
  • Lungs: breathing quickens and becomes shallower. Again, this quicker breathing takes in more oxygen for your muscles.
  • Skin: you become pale, and your face gets flushed. Blood vessels in the skin contract, directing more blood where it is needed – the muscles, brain, legs, and arms. Your hands and feet get cold because of this too.
  • Muscles: your muscles tense up all over the body, becoming primed for action. Because of this, your muscles might shake or tremble, particularly if you are not moving.
  • Stomach: you may get nausea or “butterflies” – blood is diverted away from the digestive system, which can cause these feelings.
  • Mind: thoughts begin to race. This quicker thinking can help you evaluate your environment and make rapid decisions if necessary. Hence, it can be challenging to concentrate on anything other than the danger you perceive. You may also feel dizzy or lightheaded if one does not actually run or fight under the trigger.
  • Pain: your perception of pain temporarily reduces while under the fight or flight or freeze or fawn trigger.

Since everyone’s bodies are unique, the specific physiological reactions can vary, depending on how one usually responds to stress. Understandably, after you perceive the danger is gone, it can take between 20 to 60 minutes before your body is in a normal state once again.

The Psychological (Mind) Stress Response

Along with the physiological response, it is entirely possible that one may experience psychological effects too. In the form of nervousness, acute stress tends to increase the intensity of anger or movements when evading danger.

Alternatively, it could simply cause one’s mind to blank, making it practically impossible to think clearly and decide what to act upon next. Several psychological responses can occur anxiety, focus shifts, and attention spurts.

Both physiological and psychological stress causes one’s body and mind to move into survival mode.


The stress response occurs when the demands of the environment are greater than our perceived ability to cope with them.

The stress level depends on the individual’s perception of the event and their ability to cope with the event.

E.g., taking an exam might not be perceived as a stressor by someone who has had good results on their test (they feel they can cope) but might be seen as a stressor by another individual who has failed all their tests (they feel they can’t cope this leads to a stress response).


When you feel in danger and believe you can overpower the threat, you are in fight mode. Your brain sends signals throughout your body to rapidly prepare for the physical demands of fighting.

Most signs to tell you are in a fight response include:

  • Tight jaw or grinding of the teeth
  • Urge to punch someone or something
  • Feeling intense anger or killing someone, even yourself
  • Desire to stomp or kick
  • Crying
  • Glaring at people, conserving angrily
  • Upset stomach, feels like knots or burning
  • Attacking the source of the danger


This is believing you can defeat the danger by running away. In some cases, running away is the best decision. Take a burning building as an example. Unless you are a firefighter, it is best to get out of there as fast as you can.

These emotional and physical responses signify you are in flight mode:

  • Excessively exercising
  • Feeling fidgety or tense or trapped
  • Constantly moving legs, feet, and arms
  • Restless body that will not stop moving
  • Sensation of numbness in extremities
  • Dilated eyes, darting eyes


When one feels neither like fighting nor flighting, freezing is an option. This list of responses lets you know you are in freeze mode:

  • Pale skin
  • Sense of dread
  • Feeling stiff, heavy, cold, numb
  • Loud, pounding heart
  • Decreasing in heart rate
  • Sensing tolerated stress


One may use the fawn response after unsuccessfully trying fight, flight, and freeze. The fawn response is typically prominent in people who grew up in abusive families or situations.

If you are an abused child with narcissistic parents, the only hope of survival would probably be agreement and helpfulness.

Over time, you can recognize this by realizing that regardless of how poorly a person treats you, you are more concerned with making them happy than taking care of yourself.

Why it is Important

The fight or flight or freeze or fawn response has been with us since the beginning of time and still plays a crucial role in coping with stress and threats in our environment.

One is more prepared to operate under pressure by priming the body for action. In fact, the stress created by a circumstance can be important, making it more plausible that you will effectively deal with whatever concerns you.

These triggers can help you perform better at your job or school, in a situation where you can use pressure to do well, in cases where your life is in danger, and you need to escape or defend your life.

However, while the fight or flight or freeze or fawn response happens automatically, sometimes it is activated with no real reason or danger; therefore, it is not always accurate.

Inappropriate Responses

Phobias are great examples of this concept and how the fight or flight response might be falsely activated. A person who is afraid of the ocean might experience acute stress if they go on a family cruise or visit the aquarium.

Even though typically these things are enjoyable to most of us, the person in question will experience their body going into alarm mode, with their heartbeat and respiration rate rising. If the response is severe, it can lead to a dangerous panic attack.

This kind of response is not nearly as adaptive in the modern world; in fact, we suffer negative health consequences when faced constantly with psychological threats that we can neither fight nor flee.

How to Cope

Thoroughly understanding your body’s natural fight or flight or freeze or fawn response is a way to help cope with these kinds of situations. When you begin to notice that your body becomes tense, there are steps you can take to try to calm and relax your body.

There is no doubt that the fight or flight response has a distinct purpose and function, but everyday situations like work, bills, kids, finances, and health, can be some of the largest, non-threatening stressors. Stress management is key to your overall health.

The stress response, and precisely the fight or flight or freeze or fawn response, is one of the major topics studied in health psychology. Experts in the field are interested in helping people discover ways to combat stress, which sometimes can be unnecessary, to live healthier, more fruitful lives.

By understanding the fight or flight or freeze or fawn trigger more, psychologists are helping people uncover new strategies for dealing with the natural reaction of stress.

When thinking about the fight or flight or freeze or fawn trigger, it is essential to think big picture when you begin to feel yourself starting to get worked up over something that you know is not really a genuine threat or danger.

Learning to slow down, be aware of yourself and your surroundings, and conceptualize what is truly happening to help you regain control is vital.

When to Seek Help

When the fight or flight, freeze, or fawn response becomes overly frequent, intense, and activates at the most inappropriate times, this can imply that you are suffering from a range of clinical conditions that include most anxiety disorders.

Again, while the fight or flight or freeze or fawn response has a clear purpose, it should not be activated whenever you do not actually have to defend your life.

If you feel this could be you, a valuable part of treatment for this kind of anxiety is an improved understanding of the fight or flight or freeze or fawn response’s function, purpose, and process (which is what this article is all about).

For example, patients with post-traumatic stress disorder (PTSD) may confuse the heightened physiological arousal as an indicator of a real threat.

Understanding more about the fight or flight or freeze or fawn response can help them feel safer by implementing relaxation and grounding techniques.

If you are at a point in your life where stress heavily impacts the quality of everyday living, contact your doctor. Medication, therapy, and stress management strategies can help you reach a more stable state of being.

Here is a specific list of symptoms; you should seek help if you experience any of the following:

  • Constantly feeling “on edge.”
  • Inability to relax.
  • Persistent fear, nervousness, or worry.
  • Stress interferes with daily pursuits.
  • Intense fear of non-threatening situations.

Reaching out for help is always essential. If you are worried about your mental or physical state or both, be sure to make yourself a priority.

A mental health consultant can aid in rooting the underlying causes of these overwhelming feelings.

The Bottom Line

The fight or flight or freeze or fawn response is triggered by psychological or physical threats.

It is a built-in defense mechanism implemented by evolution to cause physiological changes, including increased heart rate and heightened senses, enabling you to defend yourself rapidly from a perceived danger.

If you discover yourself experiencing the fight or flight or freeze or fawn response to extreme levels and see that you overreact to non-life-threatening situations, seek a mental health professional to help you uncover underlying causes and strategies to cope.

Now, praise yourself for taking the first step: gaining a deeper understanding of the fight or flight or freeze or fawn response.


Cannon, W. B. (1915). Bodily changes in pain, hunger, fear, and rage. New York: Appleton-Century-Crofts.

Kirby, Stephanie. “Fight Flight Freeze: How to Recognize It and What to Do …” Edited by Aaron Horn, Betterhelp,

Schauer, M., & Elbert, T. (2010). Dissociation following traumatic stress. Journal of Psychology, 218, 109-127.

What Happens During Fight or Flight Response. (2019, December 09). Retrieved from

Saul Mcleod, PhD

BSc (Hons) Psychology, MRes, PhD, University of Manchester

Educator, Researcher

Saul Mcleod, Ph.D., is a qualified psychology teacher with over 18 years experience of working in further and higher education.

Olivia Guy-Evans

Associate Editor for Simply Psychology

BSc (Hons), Psychology, MSc, Psychology of Education

Olivia Guy-Evans is a writer and associate editor for Simply Psychology. She has previously worked in healthcare and educational sectors.