This sleep stage is incredibly important.

The following story is excerpted from TIME’s special edition, The Science of Sleep, which is available at Amazon. Anyone who has nodded off on the subway, faked alertness in a meeting at work or ...

Americans may not be so bleary-eyed after all. According to Withings, a maker of health tracking devices, Americans are falling asleep these days at 11:32PM and waking up at 7:22AM—nearly a solid ...

How does your brain know when it's time to sleep? There are two main factors: Hours Awake. The longer you've been awake, the stronger your drive for sleep. Circadian Rhythm. Your body operates on a ...