The best book I have come across on trauma is called Waking the Tiger by author Peter Levine. I only started feeling better physiologically after reading it. I recommend it highly and it's unfortunately not an incredibly well-known text.
We sometimes forget that the body always remembers on a cellular level. Every physiological experience is recorded. If you experience something shocking enough, and it's not treated almost immediately, your body may ache and hurt indefinitely.
PTSD isn't even close to being well-understood by the medical community, let alone the layman, at this point in time.
Thanks again for the excellent post.
Thank you, JDM, for your insight. I have not heard of this book, but I will certainly check it out.