According to psychology books REM is sleep is when most of the dreaming occurs and it's also difficult for a person to awaken.
If a person a having a nightmare and is trying to awaken but can't is it because they are in REM sleep and can't awaken themselves or they are having a hard time?

REM means 'rapid eye movement' and I don't follow the logic that it is harder to wake during a 'busy' dream (not necessarily nightmare). They say the only time you remember a dream is when you wake during having one.

What you may be thinking of is waking up from a really scary dream state and believe you are still being pursued, stalked and being unable to move, or frozen in one spot, until your mind actually lets go of the terror and allows you to move.

Tick