Despite decades of research, scientists still don’t understand exactly how sleep benefits us. The best guess is that it enables the brain and central nervous system to work properly. Researchers are finding that sleep affects nearly every bodily system, and that poor sleep can harm health in many ways. Even if you’re a good sleeper, learning more about sleep may help you stay that way. This quiz will test your sleep savvy and help fill you in on the ABCzzz of sleep.
Estimates vary, but perhaps one-quarter to one-third of all adults—and half of those over 65—regularly suffer from insomnia, and nearly everybody has it at some time. In addition, some people get inadequate sleep because they try to squeeze in more time for work or play, while others are forced to do so by circumstances. According to the National Sleep Foundation, 60 percent of Americans say they get only a few good nights of sleep a week.
Learn more about insomnia—and its risks.
Sleep consists of four stages, which you cycle through usually four or five times a night. Perhaps the best-known sleep stage is called REM, which stands for rapid eye movement. This is when you dream.
Learn more about the stages of sleep (also known as sleep architecture).
A key player in our sleep/wake clockwork is the hormone melatonin, which is produced at night by the pineal gland in the brain and promotes drowsiness. Light, especially blue light from the sun, suppresses this “darkness hormone.” This is one way daylight contributes to alertness, and why darkness at night increases sleepiness. In contrast, vitamin D is sometimes called the “sunshine vitamin”—though it’s actually a hormone that the body produces, starting when skin is exposed to sunlight.
Learn more about melatonin.
Alcohol is a false friend for people trying to get a good night’s sleep, especially when it’s consumed in excess. It helps you fall asleep quickly and deepens sleep initially, but later it disrupts sleep and causes middle-of-the-night wake ups. Overall, it produces unsettled sleep and alters sleep phases, including reduced REM sleep, the restorative phase when you dream and your memories are consolidated.
Learn more about alcohol and sleep.
Chronic poor sleep is associated with these and many other serious health problems. Such associations do not prove cause and effect, of course. Shorter (and longer) sleep can be the result of various health problems and can worsen pre-existing health problems, resulting in a vicious circle.
Here’s more about how poor sleep affects your health.
Nonprescription sleep aids, such as Sominex or Unisom, contain a “first generation” antihistamine (diphenhydramine or doxylamine), which causes drowsiness. Nighttime pain relievers (such as Tylenol PM and Advil PM) and cold remedies (such as Nyquil) also contain such antihistamines to promote drowsiness.
Learn more about over-the-counter and prescription sleeping pills.
(a) Losing weight if you’re overweight
(b) limiting or avoiding alcohol, especially in the evening
(c) taking sedating medications
(d) avoiding heavy meals in the evening
(e) quitting smoking
(f) sleeping on your side, not on your back. (Hint: there’s more than one correct answer.)
Sedating medications such as narcotics, sleeping pills, anti-anxiety drugs, and some antihistamines can worsen sleep apnea, a disorder characterized by frequent stopping of breathing during sleep, often followed by choking and gasping to recover, repeated many times at night.
Learn more important facts about sleep apnea.
As you get older, you need as much sleep as ever. But older people tend to sleep less soundly and wake up more often—and their deep sleep stages usually become shorter.
Learn more about sleep and aging.
It is possible to catch up on your sleep and pay back your “debt,” especially if it’s a small to moderate one. But sleeping far longer every weekend to make up for sleep deprivation during the week is not wise in the long term since it throws off your circadian rhythms (that is, your body clock). If nothing else, if you sleep until noon on your days off, you may have trouble falling asleep those nights.