What is a sleep study? A sleep study, also known as a polysomnogram, is a diagnostic test that monitors various body functions while a person is asleep. It is most commonly used to diagnose sleep ...

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. Should you work out if ...

There are some obvious signs of a poor night’s sleep — fatigue, irritability and trouble focusing, to name a few — but it can also have some hidden effects. In a new study led by University of ...