REM stages and one REM stage. Ideally, you repeatedly cycle through each stage. Learn how long each stage lasts.

What if we didn't need sleep to dream? Well, scientists may have found a way to hack those benefits even when you're awake.

Hallucinogens like DMT, psilocin, and LSD might rewrite the rules of sleep, blurring the line between dreams and reality.

People on TikTok and other social media say they feel more alert when they have had fewer hours of sleep—but sleep scientists warn this is a false sense of energy ...

Deep sleep is the restorative stage of sleep. During this stage the body undergoes tissue repair, the immune system is ...

Waking up after eight hours of sleep should feel refreshing. Yet, many people open their eyes feeling just as exhausted as when they went to bed. It's ...

Stage 3 is also called slow-wave sleep. Stage 4: This stage is also called rapid-eye movement (REM) sleep due to the movement ...

Not spending enough time in the two deep stages of sleep — slow-wave and rapid eye movement, or REM, sleep — may hasten the deterioration of parts of the brain associated with Alzheimer’s ...

A new study suggests that insufficient slow-wave and REM sleep may accelerate brain deterioration associated with Alzheimer's ...

Researchers from the Yale School of Medicine found that individuals who spend less time in slow-wave and rapid eye movement ...

Not spending enough time in the two deep stages of sleep — slow-wave and rapid eye movement, or REM, sleep — may hasten the deterioration of parts of the brain associated with Alzheimer's ...