Where PTSD comes from, Part 1: Fight/Flight/Freeze Response, Physical Symptoms

We’ve spent a couple of months talking about how your survival reflex works. Well, today we’re going to talk about what it actually does.

The fight/flight/freeze response is a basic survival reflex that is built into every animal. The part of your brain that powers is is called the amygdala (uh-MIG-duh-luh. ) It’s a very primitive brain part, and we’re not consciously aware of what it does (ie., reflex is not a choice). Look at your thumbnail – that’s roughly the size of your amygdala.

When the amygdala spots what it thinks is a sign of danger, it goes into survival mode, and activates your fight/flight/freeze response.

Think of our friend that we talked about earlier – Dave the Zebra.

Although I’m sure this might seem goofy to some of you, I want you to use him as a grounding skill: anytime the discussion starts to hit too close to home, just remind yourself – we’re talking about zebras.


Cute little horsies dressed in black-and-white striped pajamas…

So – Dave the zebra and his buddies are out enjoying some pasture. Suddenly, Dave spots that lion hiding behind the big rock.

Dave’s amygdala goes into gear. His adrenal glands kick in, so he feels an adrenaline rush. His breathing gets faster and his heart rate speeds up. His large muscle groups tense up: the idea here is to get as much muscle strength as possible, to give Dave the best chances of survival.

When blood flow is focused on feeding your big muscle groups so you can run or fight, your extremities are not a priority. That’s why your hands and feet might get cold and clammy: they’re not getting a lot of blood flow.

You sweat because sweating is the body’s way of cooling off. Survival reflex expects you to have to run or fight, which heats the body up. So, reflex thinks that breaking out in a cold sweat is a nice, helpful little detail.

Since the survival reflex directs all available energy towards survival, it shuts down functions that are not essential to dealing with the immediate threat. So, your survival reflex will suppress your digestive system and your immune system, because these seem like a waste of energy when your survival is being threatened.

That, in a nutshell, are the main physical symptoms of the survival reflex. When you have PTSD, these symptoms can become chronic: that’s how you end up with chronic muscle pain, (and jaw pain from clenching your teeth); as well as chronic indigestion in some cases.

Next up – the emotional impact of the fight/flight/freeze response.


I’d love to have you share your thoughts, comments, and questions. If you do post a comment, please don’t give specific details of your trauma – these may be triggering to another reader. If you’d like to offer criticism, I’ll take it – I know I’m not perfect, and I’m always willing to learn. If you do offer criticism though, I’d really appreciate it if you could do so constructively (ie., no name-calling, please). Thanks…

You can find me on Twitter and on Facebook.

~ Dr. Dee Rajska, C. Psych.


*Fine print: Please feel free to share the link to this blog wherever you think it might be helpful! Reading this blog is a good start, but it’s no substitute for professional help. It takes a different kind of courage to admit to yourself that you’re struggling. PTSD is not a sign of failure – it’s a sign that you’ve been through a lot, and have tried to stay strong for too long. If you need help – you’re in some pretty great company. Reach out, and give yourself a chance to feel better.

**Really fine print: The content of Coming Back Home is copyrighted; please feel welcome to share the link, but do not copy and paste content. Unless otherwise noted, all original photography on Coming Back Home is the copyrighted property of Larry M. Jaipaul; please do not copy images without permission.

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6 thoughts on “Where PTSD comes from, Part 1: Fight/Flight/Freeze Response, Physical Symptoms

  1. Hi! Many times a day I would be sitting quiet and any sound,noise,touch or even the wife speaking to me I will jump out of my skin for a second! I don’t like being so jittery or nervous or what ever it is!! Is this PTSD?? Thanks for your consideration and time! PS Good info!

    1. Hi David!
      What you’re describing is hypervigilance, which is one symptoms of PTSD; depending on what other symptoms you have this may or may not be PTSD.
      Thanks for stopping by 🙂

  2. I am diagnosed with PTSD which was born in me while serving overseas. The frightening part for me is my anger response when I am challenged or provoked. Road rage or someone with an ignorant comment towards me sends me from calm to out of control in a split second & the legal consequences of this could be bad. I am 6 foot 3 & over 300 pounds of x infantry fury. I have spoken to my Councillors about this & they mention grounding but sometimes I cannot catch myself in time! To avoid risk like this, I have become more of a hermit than an outgoing social man who likes to help others.

    1. Hi Hatch!

      Thanks so much for stopping by and sharing your story.

      As you see, anger/rage is something I talked about in the very next post – it is part of your survival reflex, so when that reflex goes into overdrive, anger does become easier to trigger.

      From your description, it seems like you have some idea of where and when your anger triggers happen; if that’s the case, then this becomes a good starting point for building a “trigger map”; basically, if you know when and where you might be triggered, then you’re in a position to prepare yourself to react differently. If you’ve become “a hermit”, as you describe, then starting slowly and gently with small outings might be important to build up your comfort level gradually over time.

      Thanks again for stopping by, Hatch! 🙂

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