You could get a heart attack
Only if you're in the movie "Friday the 13th." Thanks for asking.
How would you know? You can't "know" that a person was having a nightmare when he died, and that is the absolute minimum level of knowledge that your question requires. You would also have to see a person die while having that nightmare, AND be able to show that the nightmare was the cause.
I suspect very strongly that nightmares can cause stress which could result in death, such as with people already suffering serious cardiovascular problems. But even then, would it be the nightmare that killed them or the fact that they had a bad heart?
Life turns out to be a nightmare at times.
No more than dreaming of a lottery win will make you rich.
Some folks have been literally frightened to death. Death is an escape from 'something worse'. Here it comes, now! AAUUGGHH!
Yes I died when Trump was elected president
No, science did NOT get evolution wrong.
I REFUSE waste my valuable time arguing with you about it to feed your ego. Willful ignorance can be VERY expensive and VERY FATAL.
Aughh!! This was an answer for a different questions.
Only if Freddy Krueger is in it
No but you can die IN a nightmare.
you cant die from a nightmare itself but a nightmare could trigger things such as panic attacks and things of that nature which in extreme circumstances could lead to death