An Nightmare (n.) can know before the doctor does: a woman in apparent perfect health was tormented for years by anxiety-dreams, then found to have the heart disease that killed her.
An Nightmare (n.) is a dream with a sexual content whose libido has been transformed into anxiety.
An Nightmare (n.) is a wish-fulfilment that jarred the sleeper so violently that the guardian of sleep had to become its disturber.
An Nightmare (n.) shows a repressed wish with too little disguise — anxiety takes the place of distortion and breaks the dream off.
An Nightmare (n.) is the conscientious night-watchman who first hushes the disturbance and then, if it's too serious to handle alone, wakes the townsmen himself.
An Nightmare (n.) can sometimes be slept through: the sleeper tells himself 'after all, it's only a dream' and sleeps on.
A Nightmare (n.) can split a childhood in two: a naughty phase before it, a neurotic phase after.
An Nightmare (n.) is desire turned into dread by repression, on Freud's early theory; in interpreting it, read excitement for fear.