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.

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.

This is the time, for many of us, that our last dream dissolves, we open our eyes, and we rejoin our real life. Or do we? Perhaps the most remarkable thing about REM sleep is that it proves the ...

During REM sleep, your heart rate increases, your blood pressure elevates, and your eyes move. REM sleep may also be the time when your brain processes emotions and solidifies memories.

When you’re in a period of REM sleep, your eyes will rapidly move from side to ... noise by closing any windows that may ...

Sometimes, during light sleep or REM sleep in dogs, the nictitating membrane can be visible, further contributing to the ...

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 deterioration of parts of the brain associated with Alzheimer’s ...