Getting enough sleep?

According to the 2016 National Health Interview Survey by the Centers for Disease Control and Prevention (CDC), 31.7 percent of American adults aren't getting enough sleep each night[1]. Moreover, chronic sleep disorders affect between 50 and 70 million people in the U.S. Not getting enough sleep has been linked to heart disease, kidney disease, high blood pressure, diabetes, stroke, obesity, and depression[2]. Here are some guidelines on how much sleep you should be getting a night, based on your age[3]:

Generally, the older you get the less sleep you need. Read on to learn more about what actually happens in your body when you sleep, and how to make sure you get enough of it. The following information comes courtesy of the website of the National Institutes of Health (NIH).

The sleep cycle

You may know that sleep occurs in stages. They are[3]:

Stage 1
Over the course of several minutes your body transitions from wakefulness to sleep. Heart rate, breathing, eye movements and brain waves begin to slow down and the muscles relax.
Stage 2
A period of light sleep prior to entering deep sleep. Heart rate and breathing slow, and muscles become more relaxed. Body temperature decreases and eye movements stop. Despite a slowdown in brain wave activity, there are bursts of electrical activity.
Stage 3
Deep, restorative sleep. Occurs mostly in the first half of the night. Brain activity slows down even more and the muscles are totally relaxed. It is hard to wake up someone in this stage of sleep.
REM Sleep
First happens 90 minutes into sleep. With your eyelids closed, your eyes move rapidly from side to side. Brain activity begins resembling that of wakefulness. Blood pressure and heart rate also increase to near wakeful levels. Breathing is fast and irregular. Most dreams happen during REM sleep, although some can also happen in non-REM sleep. Your arms and legs become paralyzed, so that you will not act out your dreams. Time spent in REM sleep decreases as people age.

Tips for falling asleep

If you can't fall asleep, don't lie in bed awake. Try doing an activity, like reading or listening to music, until you feel tired. If you have difficulty falling asleep or feel tired during the day, see a doctor, as most sleep disorders can be effectively treated.

Playing catch-up

Contrary to popular conception, catching up on sleep during the weekend doesn't always work. A study at the Univeristy of Colorado found that participants who were allowed 5 hours of sleep a day, but then got to sleep in for 2 days, only managed to get in an extra 3 hours of sleep across those 2 days[4]. Moreover, although these participants didn't do as much late-night eating on the nights they could sleep in, once they went back to sleep deprivation their late night eating picked up. Also, the extra weekend sleep adversely affected the subjects' body rhythms, making them more likely to wake up while their body was still promoting sleep. Finally, their liver and muscle insulin sensitivity were reduced.


1. Tables of Summary Health Statistics. Retrieved from

2. Sleep Deprivation and Deficiency. Retrieved from

3. (2019, February 8) Brain Basics: Understanding Sleep. Retrieved from

4. Reynolds, S. (2019, March 12). Weekend catch-up can’t counter chronic sleep deprivation. Retrieved from