Sleep is one of life’s most universal behaviors. Despite its ubiquity, it’s also one of the most mysterious. Humans spend ...

Ever wondered what happens if you don’t sleep for days. Sleep is not just rest—it’s essential for your brain, body, and ...

In 1959, New York DJ Peter Tripp became a test subject for sleep’s effects. His 201-hour wakeathon made him see spiders in his shoes and question his identity. This shows why sleep is essential, not ...

Sleep inertia occurs when your body is fighting to stay asleep when you want it to wake up. It generally feels like a temporary disorientation and drop in performance or mood after you wake up. Here's ...

Even a boneless, gelatinous sack lacking a dedicated anus and brain needs its beauty sleep, a new study by researchers from ...

Researchers trace how different sleep stages may fine-tune what we remember, trading specifics for more general knowledge. When you purchase through links on our site, we may earn an affiliate ...

Sign up for CNN’s Sleep, But Better newsletter series. Our seven-part guide has helpful hints to achieve better sleep. Baland Jalal lay in bed terrified ...

Breakthroughs, discoveries, and DIY tips sent every weekday. Terms of Service and Privacy Policy. The grueling Medical College Admission Test, or MCAT, was first ...

Joanna Fong-Isariyawongse does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations ...

As many as 70 million people in the U.S. have problems with sleep, and many are increasingly turning to melatonin supplements to help them fall asleep. People generally perceive these over-the-counter ...

Here are four signs she says she’d never ignore: “If your sleep issues are lasting for a long period of time (three to four ...