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.

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 ...

During REM sleep, breathing becomes faster and blood pressure and heart rate become less regular. People generally cycle ...