We are independent & ad-supported. We may earn a commission for purchases made through our links.
Advertiser Disclosure
Our website is an independent, advertising-supported platform. We provide our content free of charge to our readers, and to keep it that way, we rely on revenue generated through advertisements and affiliate partnerships. This means that when you click on certain links on our site and make a purchase, we may earn a commission. Learn more.
How We Make Money
We sustain our operations through affiliate commissions and advertising. If you click on an affiliate link and make a purchase, we may receive a commission from the merchant at no additional cost to you. We also display advertisements on our website, which help generate revenue to support our work and keep our content free for readers. Our editorial team operates independently of our advertising and affiliate partnerships to ensure that our content remains unbiased and focused on providing you with the best information and recommendations based on thorough research and honest evaluations. To remain transparent, we’ve provided a list of our current affiliate partners here.
Mental

Our Promise to you

Founded in 2002, our company has been a trusted resource for readers seeking informative and engaging content. Our dedication to quality remains unwavering—and will never change. We follow a strict editorial policy, ensuring that our content is authored by highly qualified professionals and edited by subject matter experts. This guarantees that everything we publish is objective, accurate, and trustworthy.

Over the years, we've refined our approach to cover a wide range of topics, providing readers with reliable and practical advice to enhance their knowledge and skills. That's why millions of readers turn to us each year. Join us in celebrating the joy of learning, guided by standards you can trust.

What is a Fight or Flight Reaction?

Tricia Christensen
By
Updated: Mar 03, 2024

A fight or flight reaction is a response to stress characterized by boosts of adrenaline, dilated pupils and a fast heartbeat. The term was first used in the early 20th century by Walter Cannon, an American physiologist. Cannon used the term to describe animals that underwent situations where they either had to flee or prepare to fight in order to defend themselves from danger. Such a response can also be called hyperarousal, or a response to acute stress. According to Cannon’s descriptions, when an animal is frightened or imperiled, the sympathetic nervous system responds, causing adrenaline boosts and changes in pupils and heartbeat, and sometimes extra strength shown in bursts of speed if an animal runs away or stays to attack. Some also refer to a third state “fright,” occurs when an animal doesn’t flee or fight, but panics and passes out or stands still — the typical “deer in the headlights” response or the collapse of sheep if chased by a dog.

Fight or flight reaction has also been found to occur in humans during times of stress or danger. In some cases, the sympathetic nervous system causes such extreme boosts of adrenaline that people are able to do things they couldn’t under ordinary circumstances, like lift a car off an injured loved one. The fight or flight response can be extremely powerful, but it doesn’t always work to our advantage.

People may encounter this reaction not just in situations of perceived physical danger. They may also feel imperiled during a vocal argument. This can cause them to continue arguing, and some people may even combine physical attack if their sympathetic nervous system works overtime during any type of verbal attack. Others need to flee, and if a person really wants to get out of a verbal argument, you shouldn’t try to stop him or her, since flight can be provoked into fight, if a person can’t get away from the attack and feels cornered.

Moreover, some people, especially those with post traumatic stress disorder (PTSD), panic disorder or generalized anxiety disorder, may have a fight or flight reaction for no apparent or obvious reason. The sympathetic nervous system essentially misfires, and suddenly being unable to find your keys, or something else mundane, causes a rapidly beating heart, heavy breathing, or an outright panic attack. For people with PTSD, small reminders of past traumatic events, like a smell, the temperature or being in a place familiar to where traumatic events occurred can provoke this response. For some, this can provoke aggressive behavior toward others, and yet others find themselves panicking or needing to change environments quickly.

Sometimes the flight response is not particularly overt in humans. Withdrawing from social interaction, even by watching television or surfing the net, could be viewed as a slight flight reaction when times get stressful. In studies on gender and fight or flight reaction it has been observed that men tend to become more aggressive or more withdrawn than do women under stressful situations, probably because in our culture, women tend to be more likely to lean on social resources (friends and family) to discuss their problems.

In all, most people will encounter fight or flight reaction in times of stress. Though it may have once been an instinctual behavior to protect people from danger, just as it now protects many animals, it is sometimes a hassle to deal with. Being in a full hyperarousal state can lead to bowel problems, panic, argumentative mood, withdrawal, and difficulty sleeping and breathing. If this response seems to occur frequently without stimuli, like a real danger or stressful situation unfolding, it may be wise to evaluate ways to address this response with a mental health professional or with your personal physician.

The Health Board is dedicated to providing accurate and trustworthy information. We carefully select reputable sources and employ a rigorous fact-checking process to maintain the highest standards. To learn more about our commitment to accuracy, read our editorial process.
Tricia Christensen
By Tricia Christensen
With a Literature degree from Sonoma State University and years of experience as a The Health Board contributor, Tricia Christensen is based in Northern California and brings a wealth of knowledge and passion to her writing. Her wide-ranging interests include reading, writing, medicine, art, film, history, politics, ethics, and religion, all of which she incorporates into her informative articles. Tricia is currently working on her first novel.
Discussion Comments
By anon291825 — On Sep 17, 2012

I got here following a google search to try to understand what happened to my sheep.

This morning I heard a loud noise coming from my yard but saw nothing special. When I went to feed the animals, I noticed that only one of my two sheep came to eat, which isn't normal, so I want to look for the other one. I heard some moaning coming from one of the barns and rushed over to find her lying down and struggling to get loose from a piece of fence where she got her back paws stuck.

She was obviously exhausted and very stressed from all that exertion and I wonder how long she had been there. With a lot of difficulty, I managed to got her loose and tried to help her up but she wasn't able to stand. So I helped her find a more comfortable position to calm down.

After a few minutes she seemed calmer, but she was breathing very heavily and her eyes were wide open. It seemed like she couldn't even see because she wouldn't react when I swung my hands side to side right in front of each eye.

After reading this text, I realized that what I had corresponds with what happened and trust that she will recover her energy in due time.

Thank you for this very useful information!

By geronimo8 — On Feb 14, 2011

I've heard of people doing crazy things like lifting cars before. I never really thought it was possible, but I guess I was wrong. I can't believe that our bodies are designed to do such impossible things if the situation calls for it.

I hope that if it came to a situation like that, I would be able to stay and fight.

By write79 — On Feb 11, 2011

I definitely have a tendency toward flight. I hate confrontations, and I even tend to leave the room when other people get into a debate -- even a friendly one. It just makes me uncomfortable. I know people who thrive on debating with others. I'm guessing those would be the people to stay and fight during a time of extreme stress.

When it comes to fight or flight in an anxiety filled situation, I'm gone. I realize that this may not be the healthiest way to deal with problems. Maybe, if I consciously work on it, I can change this tendency, until I'm more at a balance between the two.

I don't want to stick around when it's unsafe to do so, but I don't want to flee when I should be sticking up for myself. There has to be a good middle ground that I can reach.

By Armas1313 — On Feb 10, 2011

I have sometimes been seen as aloof because I tend to withdraw from situations at unexpected moments. This often leaves people wondering what they said, and if I had had a fight or flight reaction to them. Usually, this is not the case, but I have a personality which is seen by some as aloof. It is so difficult for me to explain to them that this is just the way I am.

By claire24 — On Feb 10, 2011

When my husband was a teenager, he exhibited a fight response when flight would have been the safer way to go.

He had the horrible experience of being carjacked, at gun point. When the attacker told him to get out of the car, he responded by telling him no, and arguing with him.

Thankfully, he eventually got out, before he was hurt. But when I heard this I couldn't believe it. I asked him why he didn't just get out of the car immediately -- it was old, and beat up, and not worth much anyway. He didn't really have an answer, but it just goes to show that when it comes to fight or flight reactions, you can't predict what you would do in a dangerous or stressful situation.

By anon22125 — On Nov 28, 2008

Can you post a biography about Walter Cannon?

Tricia Christensen
Tricia Christensen
With a Literature degree from Sonoma State University and years of experience as a The Health Board contributor, Tricia...
Learn more
Share
The Health Board, in your inbox

Our latest articles, guides, and more, delivered daily.

The Health Board, in your inbox

Our latest articles, guides, and more, delivered daily.