I would not say I have PTSD, but flashbacks, yes frequently. As opposed to making me feel like i'm in the past, they make me believe that that issue is now an immediate danger now and I start having the same anxiety symptoms as a present issue.
As far as how it starts each time: I remember hearing what people have said in the past in my head or getting this jump of suddenly remembering something and then the anxiety following.
What do PTSD flashbacks start as?