The Function of Sleep

sleepWhy is sleep so critical to our well-being? If resting in bed were all it took to recharge body and mind for the coming day, insomniacs could take in their favorite late night television and start the next day fresh. But surprisingly, it's not how much sleep you get that's important—it's the level of sleep you achieve that truly restores you, body and mind.

Sleep can be divided into two crucial phases:

  • Non-rapid eye movement (NREM) sleep takes up 80% of the average dreamer's night. The earliest phase of NREM sleep begins with general relaxation of muscles. This relaxed state eventually culminates in the deepest sleep level when it appears that protein synthesis, growth hormones, immune function, and the mind are given a boost. Delta waves—the slowest and largest waves—signal the onset of this most rejuvenating sleep level, which constitutes 50% of an adult's sleep time.
  • Rapid eye movement (REM) sleep takes up about 20% of an average sleeper's night. Dreams that occur during REM sleep might provide, in a sense, a sorting through of free-floating information. Prolonged REM deprivation has been linked to excessively anxious or emotional behavior that dissipates once more regular sleeping habits are achieved. REM sleep is thought to be the most important period for mental revitalization.

Risky Consequences From Sleeplessness

In addition to productivity and safety consequences, research shows that people who are chronically sleep deprived may also be more likely to suffer from:

Who Is Most Affected?

Late shift workers. Not only do Americans give up a good night's rest in an attempt to keep up with the hectic pace of the electronic age, many, including late shift healthcare, military and public safety workers, nuclear power plant operators, medical residents, and long-haul truck drivers, are building daily schedules against the body's natural circadian rhythm. That rhythm dictates that the longest period of sleepiness occurs during the hours of 1 a.m.–6 a.m. Thus, people who work the late shift lose out on the time that the body is programmed for the deepest and most beneficial sleep.

Older adults. The elderly, too, cope with a special set of difficulties that keeps them from getting the sleep they need. Aging brings on a host of health-related problems that interrupt sleep, such as pain from arthritis, medications with side effects that disturb rest, or depression brought on by the discomforts of the aging process. More than any other population, the elderly rely on medications that keep them up at night. Moreover, a more sedentary lifestyle doesn't allow for the expenditure of energy that results in restful sleep. Last, a slowing of what is known as delta wave activity in the brain doesn't allow for the same degree of deep sleep per night as enjoyed in youth.

But none of this means that the elderly don't need as much rest as everyone else. The combination of conditions that change the sleep habits of the elderly only indicates that they need to alter their sleep habits so that they get enough shut-eye.

Tips for Better Sleep

In general, people are so used to going without enough sleep that they don't recognize that their sleeping habits make sound slumber unlikely. Following these simple tips will help you settle down for a good night's rest. Do the following to improve the quality of your sleep as well as to get more restful sleep:

  • Avoid caffeine, nicotine, alcohol, and exercise at least four hours before bedtime. Caffeine and nicotine are stimulants, and alcohol, though a depressant that makes falling asleep easier initially, interferes with deep sleep later on during the night. Exercise also acts as a stimulant, but a workout earlier in the day can improve nighttime rest.
  • Leave worrying outside the bed. If you stay awake worrying about things you have to tackle the next day, write out a list of "to-dos" to take the pressure off. Then put the list aside to deal with the next day.
  • Keep other activities out of the bedroom. Don't confuse your bedroom with your family room. Keep your television viewing and internet surfing out of your sleeping quarters. You need to associate your bedroom with sleep and not activities that will keep your mind engaged.
  • Don't try to "force" yourself to sleep. You'll just lie awake staring at the clock. After 20 minutes of wakefulness, go to another room to read or perform some other quiet activity. Return to your bedroom only when you've become tired enough to sleep.
  • Temperature counts. Keep your bedroom set up for a restful night's sleep with a comfortable mattress and proper temperature setting. A too-hot or too-cold room can keep you awake.
  • Reduce noise levels. Apartment-dwellers with noisy neighbors or those on heavily trafficked streets can block out noise with a fan or sound-simulating machine that mimic nature sounds (such as the ocean or rain).
  • Avoid stimulation before sleeping. Try not to engage in anything that will give you a second wind just before bed, such as viewing an action-packed movie or sitting in a brightly lit room. Instead, try listening to soothing music or reading.
  • Slow down. Don't hurriedly get ready for bed at the last minute. Brush your teeth and wash yourself a while in advance. Try to stick with an early-to-bed, early-to-rise pattern. That way, you won't go to bed too late during the work week and need an alarm clock each morning to wake you out of a sound sleep.

If you're troubled with chronic difficulties falling asleep—or staying asleep—see a doctor. You may discover, for example, that what seems like simple snoring is actually sleep apnea. Other sleep disorders, such as restless legs syndrome (unpleasant sensations in the legs combined with irresistible urge to move) and narcolepsy (sudden and involuntary episodes of sleepiness) should also be discussed with your physician. Along with treating specific disorders, physicians can prescribe general sleep aids.