On average, you have between one to six dreams a night, the strongest occurring during REM sleep. Nobody remembers all the dreams they have, but if you've ever woken from a particularly unsettling ...

Sleep disorders are problems in sleep that meet diagnostic criteria for a disorder. They include insomnia, obstructive sleep apnea, parasomnias and narcolepsy.

Dreams are imaginary sequences—some with clear narratives, and some without—that play out in people’s minds as they sleep. Most dreams consist of a series of images, sensations, and emotions ...