HOUSTON — A good night’s sleep is important for both the body and brain. It’s essential to understand the four stages of sleep and how to get more restful z’s. Stage 1: Transitional sleep The sleep ...

It can be tough to calculate exactly how long you’re in REM, but many health trackers use your heart rate, heart rate variability, and data on your movements to make solid estimations. (Just know that ...

Deep sleep refers to slow-wave sleep — a stage in the sleep cycle when brain waves slow down. Getting enough deep sleep is crucial for numerous bodily functions. But how to increase deep sleep isn’t ...

Sleep is kind of a big deal. It’s the best way for our bodies to recover after a hard day, and it also greatly influences our cognitive functions and immune responses. Yet while many of us focus on ...

Sleep is a fundamental aspect of our lives. It is a natural process that rejuvenates our bodies and minds, allowing us to function optimally during our waking hours. However, not all sleep is the same ...

You may remember little to nothing when you wake up, but there’s a lot going on while you sleep. You just spent the previous seven to nine hours moving through a highly structured cycle of sleep ...

In general, most adults need between seven and nine hours of sleep per night. Someone who gets this recommended amount will generally go through between four and six sleep cycles (all of the sleep ...

A 2021 phone poll revealed that only 34% of Americans "sometimes" remember their dreams. About 1 in 10 say they "almost always" can, and the same percentage say they "never" do. Explanations for such ...

Sleeping for 7 to 9 hours at night isn't the only way to catch some z's. Here are four alternative sleep cycles -- and they're pretty obscure. Annie Miller Medical Reviewer Annie Miller is a licensed ...

Ever wonder why some mornings you wake up ready to go, and others you feel like a zombie? The difference often comes down to when you wake up during your sleep cycle, and that’s exactly what a sleep ...

I'm energized after 7.5 or 9 hours sleep, but groggy after 8. A sleep expert tells me why.

What happens in the brain and body during NREM and REM sleep As you sleep, your brain cycles through four stages of sleep. The first three are considered non-rapid eye movement (NREM) sleep, also ...