A lot is written about PTSD, on the internet, in books, about possible causes, the symptoms, the various treatments (EMDR, sports, group talks etc.) and the different types of trauma (acute, complex, chronic) causing PTSD. All very helpful but I wanted to know what happens the very moment PTSD starts, what is the crucial factor that ignites PTSD, what is physically happening. I had read about a blockade in the brain, what, were, why, how? I never found an answer.
On my homepage I tell you why I am interested in PTSD. Because I wanted to learn the answer on above mentioned question I did a course for Trauma coaching, not to be a coach, I leave this to very specialized people, but to see if I could find an answer. And I did.
This website is just about that, written in normal language so everyone can understand what is the basic of PTSD.

The ignition of PTSD starts with a terrifying moment or an accumulation of trauma.
You all can imagine an example or have ever experienced one.

Four parts of your brain are involved in the process causing circumstances for your body to react to survive the terrifying moment (see 1).

Immediately after your brain has received a ‘danger’ signal by your senses (feeling, smelling, seeing, hearing or tasting), your brain sends signals to your body to react by releasing lots of adrenalin to get you into action to survive. Surviving is an instinct, you react often without knowing that you are reacting. The adrenalin gives you the energy to react immediately, to fight or run but sometimes the adrenalin shot is so high that it shuts down the limbic system (amygdala, hippocampus and hypothalamus (see 1)), the energy comes to a abrupt halt, blocks with a shock. You can become immobile, frozen, or you start fighting but don’t remember that afterwards because of the blockade of energy. Information but also the traumatic event are difficult to remember and to understand. If the state of immobility takes too long, if you are not able to release all the stucked energy by fighting or running or any other active reaction, it will block, or partially block, the pass way to the prefrontal cortex (thinking, reasoning, understanding brain). The prefrontal cortex notices that something is wrong and will keep on trying to recover and to tell you the ordeal is over, but it can’t because there is no context between the emotions (anxiety, fear) and the random images that were able to reach the prefrontal cortex. This resulting in nightmares and flashbacks. From then onwards you are stuck in the moment of the terrible experience. The very high energy level stays in your nerve system which will stay constantly alert, your senses keep on scanning the world around you, interpreting normal things, like a car backfiring, laughing people, as dangerous, making you feeling scared or angry, your prefrontal cortex can’t tell you you’re safe. Your nerve system is warning you constantly for danger, this can also happen when your nerve system is shocked time after time. Your stress level don’t have time to go down, it levels up. The balance in your brain is gone until this disturbance is fixed and the pass way to your prefrontal cortex is open again, balance restored, then you will have control again.
Often this problem solves itself, your brain notices that there is something wrong and starts healing itself. But very often it can’t, it is to severe, you can’t do anything about this.
If you are not back in control after a month, it is wise to ask for help from specialized people because your brain is not able to heal itself, the obstruction is to severe and from there on things will only get worse.

As I said your brain will try to heal itself. It will try to solve the problem time after time after time, like a computer that can't start but keeps trying over and over again, you see the same info on the computer, that doesn't start, over and over again. Your brain is blocked in the moment of trauma so you will relive that moment again and again in flashbacks and nightmares. This and other to PTSD related problems will follow because of this (see 2). You don’t sleep well or don’t want to fall asleep, you get tired because lack of sleep, you get agitated, short of temper, your behavior will change etc..
Your brain tries to solve and pass this blocked station but it can’t without the help of a specialist, like the computer. It will stay blocked until you make a step forward and that is to ask for help from a specialist who can help you to remove the blockade of energy and restore the energy balance in your body. It is such a ‘tiny’ problem but not easy to fix, it will take time and courage. Take this step forward and you can leave the past finally behind and look to a much better future. Ask people to help you in this.

And just that, asking for help, can be a huge problem. If you can't reason, think or understand what is going on, if you are not able to see the context, you might think that everything is normal, you don’t realize that you are not your normal self, you will not believe people who are telling you that you have become a different person (see 2). But maybe you might feel, deep, deep inside, that there is something different.
Then trust people who you have known all your life, who advise you to ask for help. If people beg you to be wise and ask for help, you might not realize how bad the situation is. The disturbance of energy will not go away by itself anymore. I am sure that you don't want your life to be quarreling with everyone you once loved, fighting with friends because you don’t trust them anymore, being suspicious and losing your family and feeling very unhappy because you know that this will be your future if you don't take a step forward, you have seen it happen to other people. Change is possible, you have read this paper, knowledge is power!

PTSD is not a mental illness or a disorder, it is a disturbance of energy caused by a very normal bodily reaction on a very unusual situation and it can be cured, life can be much better. PTSD is not a weakness, anyone from anywhere can be affected by trauma, now it happened to you, next time it’s me. But you can be more your normal self than you are now. Trust the people who know you best. You have probably seen what it does to people who didn't have/want help. Is it that kind of life or a much more normal life you want, make your choice. But having PTSD it is easier to make no choice, to just go on but PTSD will not leave you or go to sleep, on the contrary, it will take you over and the more you try to suppress it the more it will fight to come to the surface, PTSD will be your life. Living like that is much worse than asking for help, having a treatment for some time together with people who have had the same experiences, treatments like EMDR, group talks, sports and more, to get rid of this mass of energy. You are not alone. And during this process you can help other people, being there for them as they are there for you, inspire them, you are not a patient!
There are ways to regain control with help from specialized people. Asking help is not a weakness, it’s wisdom, it shows strengths. 

And PTSD can change your DNA, do you want your future children and grandchildren to suffer like you are doing? Don't let a traumatic experience rule the rest of your life and the lives of the people you love and who are loving you! You deserve it, they deserve it, they are depending on you! Choose, and your choice decides who you are. Trust me, there will be a day that you can say: ‘I’m back!’

I wish you all the strength you need and my best wishes and warmest regards!