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

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 ...

Not spending enough time in the two deep stages of sleep — slow-wave and rapid eye movement, or REM, sleep — may hasten the ...

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

New research shows that reduced time in slow wave and REM sleep is associated with smaller brain volumes in regions ...

As most people who have pulled an all-nighter will agree, lost sleep can leave us feeling foggy and far from our best. In ...

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

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 ...