Healthy Sleep
What constitutes healthy sleep? The amount of sleep you get is extremely
important. But the type of sleep you get also determines how well-rested
you’ll be when you awake.
Why you need good sleep
You need good sleep so that you can function well — both mentally and physically
— during your waking hours. Good sleep can enable you to work productively,
make sound judgments, avoid harm, and interact with other people effectively.
Sleep also helps us in less visible ways. During sleep, the body secretes a hormone
that repairs and regenerates tissue throughout the body. Sleep may also be instrumental
in reinforcing our memories and, some experts believe, essential to processing complex
emotions.
Your personal sleep needs
Different people require different amounts of sleep. The vast majority of us need
between seven and nine hours of sleep each night. Some people need more than nine
hours, and that’s perfectly normal for them. Some others can sleep less and
wake up completely refreshed.
How to know if you’re getting enough sleep
You should sleep uninterrupted. When you wake up, you should feel well-rested and
ready to go. Most importantly, you should generally have no sleepiness during the
day, even when involved in boring or mundane activities.
If you’re feeling drowsy during the day, you may not have gotten enough quality
sleep.
The types of sleep you need
In healthy sleep, we experience different kinds of sleep and — just as important
— we experience them in a particular sequence of stages.
There are two primary sleep stages.
Non-rapid eye movement (NREM) accounts
for longer periods of sleep during which our brain activity and bodily functions
slow down. Rapid-eye movement (REM)
happens in brief spurts of increased activity in the brain and body. REM is considered
the dreaming stage of sleep.
Healthy sleep is characterized by a specific “sleep architecture,” or
sequence of stages. The sleep cycle
usually begins with a period of about 80 minutes of NREM sleep followed by about
10 minutes of REM sleep. This 90-minute cycle is repeated four to six times each
night. If the sequence is interrupted (for example, by external noise or a
sleep disorder), the quality of our sleep suffers.