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

Research reveals how specific sleep stages protect brain vulnerable to Alzheimer's, offering hope through simple lifestyle ...

On an Apple Watch, "core sleep" is another name for light sleep, which scientists also call stages N1-N2. It is not a type of ...

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

Heart rate, breathing, and brain waves become more regular. Stage 3 is also called slow-wave sleep. Stage 4: This stage is ...

New research shows that reduced time in slow wave and REM sleep is associated with smaller brain volumes in regions vulnerable to Alzheimer’s disease.

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

Disrupted SWS (critical for waste clearance) and REM sleep (key for memory) may impair the glymphatic system, hindering the ...

Need another reason to prioritize your sleep? 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 ...

Can poor sleep raise your risk of Alzheimer’s? A new study links reduced sleep stages to brain shrinkage in areas prone to ...