Someone who's to terrified to get in bed, night after night, may suffer from hypnophobia, a fear of falling asleep.
Everyone's scared of sleeping sometimes — especially kids, and people who watch horror movies right before bed. If that fear grows debilitating, it may become hypnophobia, a condition that disrupts people's lives and can be treated with therapy. Some people with hypnophobia dread closing their eyes at night because of earlier experiences with nightmares or sleep paralysis, while others simply have extreme anxiety that flares up at bedtime. This word's Greek roots mean "sleep" and "fear."