Fight or Flight Theory of Panic Disorder

Woman sitting on floor with head in her hands
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The fight or flight response is a physiological response to a stimulus which our bodies consider dangerous or life-threatening. This response—also called the acute stress response—is familiar to most people as the intense feeling of anxiety, shaking, and fear that can occur when our bodies prepare for a possible emergency.

First described in the 1920s, the fight or flight response is the first part of the involuntary general adaptation syndrome. In the fight or flight response, stimuli result in stimulation of the sympathetic nervous system.

The sympathetic nervous system then sends a message to the adrenal glands which result in the release of the stress hormones, epinephrine (adrenaline), norepinephrine (noradrenaline), and cortisol, among others. These hormones, in turn, lead to the symptoms associated with the response.

The counterpart to the flight or flight response is the relaxation response, in which the body goes back to normal. The "recovery period" between a fight or flight response and normalization of body functions is variable but often lasts for 20 to 60 minutes following stimulation if the perceived threat disappears.


The fight-or-flight response is a stress reaction that likely evolved out of the survival needs of our early ancestors living with the daily dangers of the time. To demonstrate, imagine you’re a prehistoric cave dweller relaxing one evening and enjoying the daily catch.

Suddenly, a large and hungry saber-toothed tiger appears on your doorstep. To him, you look like a tasty morsel on the food chain. But, human design kicks in with a surge of strength and energy, increasing your chances of surviving this encounter.

Fight or Flight and Panic Disorder

Some theorists believe that this stress reaction is seen in the common fears associated with modern day panic disorder, specifically, in the fear of large open spaces or being in situations without an easy escape route. In the dangerous world of our ancestors, crossing a large open field leaves one vulnerable to attack. The same can be said for being cornered without any means of escape.

When the Response Is Triggered

Researchers have identified numerous physiological changes that occur during the flight-or-flight stress response. As noted above, these changes are believed to be triggered by the sympathetic nervous system through the release of stress hormones into the bloodstream. This release causes immediate physical reactions in preparation of the muscular activity needed to fight or flee the threat.

Some of the changes during this process include:

  • Increased heart rate
  • Rapid breathing
  • Changes in blood flow: Increased blood flow to muscles necessary for escaping, such as skeletal muscles, and decreased blood flow to tissues not necessary for escaping, such as the smooth muscles associated with digestion
  • Dilation of pupils
  • Auditory exclusion, also known as hearing loss
  • Tunnel vision, or a loss of peripheral vision in order to fully focus on the danger at hand
  • Sweating to cool the body in response to the heat generated as your body gets ready to contend with a predator

These physical changes occur rapidly and automatically. If one were experiencing a life-threatening event, they would be expected. But, when they occur while picking up a few groceries for dinner or sitting in a meeting at work, they can be quite frightening. Since much of the stress in our current day society is psychosocial stress, this prehistoric response which once was necessary for survival could even be detrimental.

Fear Without Danger

During a panic attack, the body’s alarm system is triggered without the presence of any danger. It is the absence of identifiable danger that actually intensifies the fear associated with panic attacks. If there is an identifiable danger, we can fear the danger, not the symptoms.

However, if there is no danger and someone experiences sweating and changes in heart rate, breathing, vision, and hearing, it would seem logical to fear the symptoms, even believing they are life-threatening. Physically, your body is telling you to get ready, because you are in grave danger. But how do you prepare psychologically for certain danger that is unseen?

It may be that you assign the symptoms mistaken meaning. It may be that you immediately flee the situation as if it were dangerous. But these thoughts and actions don’t get you out of danger. They only reinforce and strengthen the association of a fear that is not based on an actual threat.


Since the fight or flight response underlies many of the symptoms common with panic disorder, researchers have investigated ways of taming this response. It doesn't work to just say "I'm not stressed," since the response is involuntary.

The treatment for panic disorder most often includes several modalities, including both medications and cognitive behavioral therapy. One method of treating the disorder, desensitization, takes into account the fight or flight response. In this method, people with panic disorder are gradually exposed to anxiety-causing stimuli while learning to control their anxiety and panic simultaneously.

Breathing exercises and other stress reducers can be helpful to help calm the body after the initial fight or flight reaction has occurred. Since many people, even those without panic disorder, cope with a level of stress that could be detrimental rather than helpful to the body (unlike "eustress"), taking a moment to check out ​stress management techniques may be just what the doctor ordered.

5 Sources
Verywell Mind uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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By Sheryl Ankrom, MS, LCPC
Sheryl Ankrom is a clinical professional counselor and nationally certified clinical mental health counselor specializing in anxiety disorders.