I have had PTSD symptoms for years now, and I think that it is possible that dreams can cause PTSD because physical interactions are registered through our brain, as are nightmares, so, really the only difference is one situation is real and the other you simply think is real. They still have the same effect.
I have had nightmares everyday or mostly 5 to 6 times a week, where I am fighting for my life. I actually have flashbacks about them and think about what actions I took to survive. I remember my nightmares too, long after they happen. I would wake up sweating and my heart racing. Later in the day, weeks, months, and years later I can still remember those especially traumatizing nightmares. I have had rape nightmares and remember them. I remember giving birth multiple times and having the child taken away. I never gave birth in real life. But I think about the child. My second one comes and goes in my dream world. I try to protect him or her when she appears. I remember battles, wars, zombies, demons, witches, spirits, and all kinds of enemies trying to kill me and having to fight to survive. The nightmares were never real, but I remember them and can't forget them. I wonder if I have ptsd but not to the extent that it affects completely my life. I feel like if I took a polygraph exam and was asked did I kill anybody, I would fail because I think about the zombie and demon attacks I fought against. I hope more answer this question as I wonder if anyone is like us.
I don't have nightmares every night. They happen randomly with large intervals in between.
if you have a nightmare every night i would think so :)