When I get triggered I lose rational thought. There are lots of racing thoughts, and I usually appear a little manic, but skittish. Either i don't talk at all or, if forced to, i blather incoherently in metaphors about what is going on in my brain. That usually freaks people out around me, but is sometimes funny in retrospect. Most of the time i dissociate and watch myself be crazy or awkward in the social situation. I'm too afraid to tell those around me what is going on.
The physical side of it is more difficult for me to describe. I breathe faster, my heart races. I sweat through everything I have on. I fidget and close myself into a room. lock doors, windows, shut blinds, get my baseball bat even though I know nothing in coming after me anymore.