- By Jason Howland
Mayo Clinic Minute: What are the stages of sleep?
Sleep is important for good health. Experts say eight hours of shut-eye is a good idea for most adults. And whether you're a sound sleeper or someone who has trouble sleeping, your body goes through sleep stages.
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When your head hits the pillow, your body can go through several stages of sleep.
"We basically divide sleep into wake, non-REM — three types — and REM sleep," says Dr. Lois Krahn, a Mayo Clinic sleep medicine specialist.
Dr. Krahn says the three types of non-REM, which stands for rapid eye movement, include level one, which is light sleep; level two, intermediate sleep; and level three, deep sleep.
"When we're in deep sleep, our heart rate and our breathing really slows down," says Dr. Krahn. "And that just allows the body a chance to recover from the busy day."
The final stage is REM sleep, which is typically when you dream.
"Things speed up except a person cannot move," says Dr. Krahn. "They're paralyzed, and that's actually felt probably to be a rinsing function — to clear the brain of toxins and byproducts that have collected during the waking day."
Dr. Krahn says not everyone goes through all of the stages. Some may skip one or two. But, in general, people alternate among several different levels of non-REM and REM sleep every night.
"The longer you spend in deeper sleep, the more refreshed you'll feel in the morning," she says.