That's like being asked to identify the critical features of bigfoot based on a grainy photograph that's also suspiciously confusing and difficult to discern.
Well, it's kind of a big deal... scary but somehow human?
I've tried describing it from a somatic perspective, a behavioral perspective, a metaphorical perspective, and even from an interpersonal perspective that's sometimes made life with PTSD vastly more challenging. The reality is that everything might seem relatively fantastic for hours to days on end before encountering something that shifts me into that other world, manifested by the same uncertainty and monsters.
I labor over headaches, fatigue, chronic pain, generalized waves of anxiety, and avoidance/isolation. When I'm faced with the worst of the worst, I shut down. There may be loads of cues, but the perspective shift jettisons my senses into a memory bank of an unrelenting Hell. In the neurological sense, my brain processes everything differently: alarm bells are hyper, the rationale and sensory systems slow down, my ability to remember what's presently occurring diminishes, perceptual regions of the brain lock onto sensory-based memories, and lateral communication between both hemispheres of the mind lose connectivity.
It feels like walking out of my body, and nobody else has time for the change.
Definition: Extreme form of anxiety with frightening memories/flashbacks, nightmares, and intrusive thoughts about traumatizing events. Symptoms must persist for over a month. Symptoms persisting less than a month may be related to Acute Stress Disorder.
Many leaders of the debate hold that the word "disorder" should be replaced with "injury." The belief is that reclassifying PTSD to PTSI would reduce stigma while further encouraging people to recognize that the post-traumatic stress is a result of an external injury to the brain.