To writhe with agony; to suffer violent anguish.
To struggle; to wrestle; to strive desperately, whether mentally or physically.
To cause agony or anguish in someone.
To have a nightmare.
Any bad, miserable, difficult or terrifying situation or experience that arouses anxiety, terror, agony or great displeasure.
A very bad or frightening dream.
A feeling of extreme anxiety or suffocation experienced during sleep; Sleep paralysis.