When you buy through links on our articles, Future and its syndication partners may earn a commission. Credit: Getty Images There are tell-tale signs when you don’t get enough REM sleep. It’s the ...

Sleep Cycles: One rapid eye movement (REM) stage and three non-REM stages that altogether last about 90 to 120 minutes Benefits: Physical and mental recuperation and memory consolidation Disorders: ...

Ever woken up in a cold sweat after a terrifying or twisted dream? You’re not alone. Here’s what science says about why ...

Deep sleep refers to slow-wave sleep — a stage in the sleep cycle when brain waves slow down. Getting enough deep sleep is crucial for numerous bodily functions. But how to increase deep sleep isn’t ...

Poor sleep has been linked to an increased dementia risk, though we don’t yet know exactly how one affects the other. But roughly 90% of people with the sleep condition known as isolated REM sleep ...

Whether it's hormones or family and societal pressures, many women feel they need more than eight hours of sleep. Turns out ...

Night terrors are characterized by bouts of screaming, thrashing and panicking in one's sleep. They can be caused by lack of sleep stress, or PTSD.