Someone mentioned "threat to physical integrity", apologies if I read this out of context but although I do agree with this statement, it is not only the physical threat that is involved to result in PTSD but the coupling with threats to Psychological integrity too - those feelings of intense helplessness, fear, horror etc. - they are all psychological insults that we have never had experience with until the *traumatization threshold* is reached. These insults result in what I call the distinctly psychological components of the injury, things such as guilt, shame, defensive thinking, etc. (which then give rise to mood/behavior changes).
My therapist talked to me of the concept of Cognitive Dissonance, where we tend to experience discomfort when confronted with information that goes contrary to our ingrained beliefs. We are confronted with two conflicting beliefs and we try to resolve them in the only way we know how, that way is purely individualized and can only come from the person. Cognitive dissonance is not unique to PTSD, everyone has the capacity for it, however when dealing with PTSD our ability to resolve dissonant conflicts in belief are further heightened. We react defensively, angrily and our behaviors can spiral out of control as we spin our wheels in the dirt trying to resolve inner conflicts.
From a purely personal perspective, I still have difficulty with my self identity concept, the dissonant issue being that I lived my life the way I believed it should be lived following all societal imposed norms /mores and not the way that I wanted to live, thus denying myself certain freedoms throughout my life. The person I thought I was no longer exists and I have to struggle to find out who this person really is as the thin veil covering that person was removed by trauma. Tough concept to swallow, yet alone find resolution to, as I struggle against the idea that I am now somehow "different".
It is perfectly normal for someone with PTSD to get highly defensive over the smallest things, we view these cognitively dissonant issues as personal attacks and we react to protect our longest held beliefs. Each pang of internal pain is simply the result of our injured Self reacting to yet another threat to our psychological integrity, the integrity that was damaged as a result of trauma.
Forgiveness, a compassionate stance in what we encounter and excruciating patience will aid us in healing.
I can't cite sources for my statements, my scattered mind likely couldn't find them in the myriad of research papers I've read over these years, rather, I speak from personal experience, un-cite-able knowledge, and a rapidly growing and heightened sense of self awareness.