Add Yahoo as a preferred source to see more of our stories on Google. A woman stretching after sleep. When it comes to rest, people tend to think about it in terms of being awake or asleep. However, ...

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

Have you ever slept for a full eight hours but still felt completely exhausted? You might not be getting enough of the right types of sleep. Today, many people use smart watches or rings to track ...

Valerie Cacho, MD, is a board-certified sleep medicine specialist and the founder of the online educational company Sleephoria. Make sure you follow a consistent sleep schedule to help regulate your ...

Have you ever wondered what actually happens in the brain during sleep? While your body appears still and at rest, your brain remains highly active, carrying out essential processes that keep you ...

To see your sleep data, open the Health app on your iPhone and tap Browse, then Sleep. At the top of the screen, you will see ...

Beth Skwarecki is Lifehacker’s Senior Health Editor, and holds certifications as a personal trainer and weightlifting coach. She has been writing about health for over 10 years. Let's talk about one ...