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What Is the Fight or Flight Response?

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When faced with fear, the typical responses are to either fight what we’re afraid of or run away from it. This stress response is called “fight or flight,” and it could save your life.

What Is Fight or Flight?

When something scares you, your body and mind react in a very distinct way. The acute stress response, or fight or flight, occurs when your fear causes your brain to release hormones into your body that tell you to run or put up your fists to fight.

Fight or flight prepares you for danger, and it has been a response ingrained in humans since our ancient ancestors lived. While humans have always had the fear response, “fight or flight” wasn’t coined as a term until 1915. Dr. Walter B. Cannon studied the fear response of lab animals, which lead to his understanding of the way humans respond to extreme stress caused by fear and trauma.

How the Fight or Flight Response Works

When something occurs that makes you feel fear or acute stress, such as getting in an accident or getting on stage to speak in front of strangers, you experience a set of reactions that are a sign of the fight or flight response. It’s this sudden release of stress hormones that stimulates your stress response, provoking your adrenal glands and your sympathetic nervous system to release hormones. The hormones released include adrenaline and noradrenaline.

Your fight or flight response can kick in even when you’re only minorly startled, such as when the neighbor’s dog suddenly growls at you when you step outside your door. While you know that the dog is fenced, your mind and body respond quicker than you can rationalize the fear.

Symptoms of this stress response include:

  • Rapid heart rate
  • Increased blood pressure
  • Faster breathing
  • Muscles tensing up
  • Flushed and pale skin
  • Shaking
  • Dilated pupils
  • Increased perspiration

Each symptom has a purpose. Your body is preparing you to either get away or do something drastic about what’s frightening you. It’s giving you more energy, making your senses keener, and also preparing your blood to clot faster in case of injury (which is why your skin alternates from flushed to pale during your fear response).

Once you’re safe from impending doom, it takes your body anywhere from 20 minutes to an hour to get back to normal.

What the Fight or Flight Response Is Doing for You

The fight or flight response is about more than just making your nervous and feel scared—it has a purpose that relates to your survival. It’s a primal response, as already mentioned. However, it can be triggered by real events or imaginary threats.

All of those responses you have to fear are helping you get ready to deal with your fear. Stress is motivating for some people, so your fear response could push you to perform a job better or get your work done on time. Those are non-life-threatening things that cause stress in people’s lives, but those things can still trigger a fear response in the right situations. While this may seem a bit over-the-top, the response is an automatic human reaction, so it isn’t always correct.

Phobias can sometimes be based in real fear, such as having a fear of dogs (it’s possible to be mauled by a dog). However, most of the time, they are irrational fears that aren’t likely to kill you.

You may think you’re going to die when crossing a bridge that is completely sealed in simply because you’re afraid of heights. You’re not likely to die (unless you have a heart attack from your fear), so the response isn’t really to anything but getting you to move and exit the bridge. You’re more likely having a panic attack, in this case, which feels similar to the fight or flight response. It may make you avoid walking on bridges in the future as well.

When you do start to have the symptoms of an acute stress response, and you’re not in a life-or-death situation, you can take actions to help calm yourself. Use relaxing breathing techniques and see the situation for what it is.

When the situation revolves around your actual survival, the symptoms of fight or flight will help you get through it. Your body will get ready to flee the situation or to fight to stay alive. Your eyes will dilate so your vision will be more acute, and you can get away or fight with more precision. Your heart rate will speed up so that you have the energy to fight or run.

Which Response Is More Likely?

Whether you run away or stick around depends on who you are and the situation you’re in. A child who feels fear is more likely to run. If you’ve had some sort of defensive training or you’re carrying a weapon, you may be more inclined to stay and fight.

Yvonne Glasgow Yvonne Glasgow
Yvonne Glasgow has been a professional writer for almost two decades. Yvonne has worked for nutritionists, start-ups, dating companies, SEO firms, newspapers, board game companies, and much more as a writer and editor. She's also a published poet and a short story writer. Read Full Bio »