What is core sleep is on your Apple Watch, and does it even matter? We look at which sleep stages matter most for quality ...

REM sleep goes even deeper into brain recovery, dreaming and processing memories and emotions. This is the sleep stage in ...

Light sleep is the beginning of your sleep cycle and your body's way of winding down. Breathing, heart rate and muscle changes prepare your body for the deeper sleep to come. Light sleep is broken ...

Sign up for CNN’s Sleep, But Better newsletter series. Our seven-part guide has helpful hints to achieve better sleep. Need another reason to prioritize your sleep ...

REM stands for rapid eye movement — a stage in the sleep cycle when your brain is almost as active as when you’re awake. Getting enough REM sleep is crucial, as it helps you store information and ...

Whether it's a routine to improve sleep hygiene or a trick to fall asleep faster, most of us are pretty interested in how we can rest better without taking hours out of our day. Of course, we all know ...

Need another reason to prioritize your sleep? Not spending enough time in the two deep stages of sleep — slow-wave and rapid eye movement, or REM, sleep — may hasten the deterioration of parts of the ...