Ever wonder why some mornings you wake up ready to go, and others you feel like a zombie? The difference often comes down to when you wake up during your sleep cycle, and that’s exactly what a sleep ...

Sleeping for 7 to 9 hours at night isn't the only way to catch some z's. Here are four alternative sleep cycles -- and they're pretty obscure. Annie Miller Medical Reviewer Annie Miller is a licensed ...

Learn facts about sleep, during which the body rests, recuperates and performs essential repairs. When you purchase through links on our site, we may earn an affiliate commission. Here’s how it works.

You’ve heard of REM sleep but what about deep sleep? Experts share why it’s important and how to make sure you’re getting enough of it.