However, some research shows that major stressors may increase REM sleep but reduce deep sleep. REM rebound, which is when we ...

Night terrors tend to happen in a sleep stage known as deep sleep, rather than when in REM, which is when nightmares happen.

Most people spend a third of their lives sleeping, but you may need more or less than eight hours a night. The amount of ...

Sleeping in pitch-black darkness might not be the key to better sleep. Here’s why a little light at night could actually help ...

More people are becoming obsessed with sleep trackers, causing insomnia and making sleep worse, experts say. Here’s how to ...

We experience multiple sleep cycles in a night that are defined by time spent in different sleep stages. At the end of these sleep cycles, it’s very common for us to briefly wake up before ...

ETH Zurich researchers found that pupil size changes during sleep, indicating shifts in brain activity. This could help ...

A new study reveals that pupil size fluctuates constantly during sleep, reflecting changes in brain activation levels.

“Sleep architecture refers to how we cycle through different sleep stages: light sleep, deep sleep, and REM. Each stage serves a purpose. For example, deep sleep is essential for physical repair ...

Scientists have discovered that our pupils continue to change size while we sleep, revealing unexpected fluctuations in brain ...

Researchers at University of Tsukuba found that, for female athletes, differences in daily training and reproductive function produced different phenomena in sleep stages and energy expenditure ...