It's 2 a.m. The house is quiet, cloaked in the stillness of the night. Then, a shuffle. A door creaks. A child walks down the hallway, eyes wide open but fast asleep. Elsewhere, someone mumbles ...

Sleep Cycles: One rapid eye movement (REM) stage and three non-REM stages that altogether last about 90 to 120 minutes Benefits: Physical and mental recuperation and memory consolidation Disorders: ...

Sleep is more than a way to pass the time. It's a place for us to dream, relax, and most importantly: rest! Getting some shut eye might not be the most exciting thing in the world, but it's critical ...