Who Needs Sleep?

Who Needs Sleep?; Weir, Kirsten

Current Health 2 10-01-2005

Who Needs Sleep?

Byline: Weir, Kirsten

Volume: 32, Number: 2, Page: 16. ISSN: 0163156X

Maybe you do. Here's what you need to know about slumber, from A to Zzzzzzz's.

Quick quiz: How much of your life will you spend sleeping? Answer: A whopping one-third. For something we spend so much time doing, we don't often give slumber the credit-or attention-it deserves. A study by the National Sleep Foundation (NSF) found that 60 percent of middle and high school students felt tired during the day, and 15 percent had fallen asleep in school during the last year. "I'm definitely tired during'the week," says Leah Schaffer, a 17-year-old junior from Oxford, Mich. "I nod off a lot in chemistry." But why is sleep so important? And why are so few of us getting enough?

Sleeplessness Kills

When we sleep, we cycle through five welldefined stages. Between stages 1 and 4, we sink deeper and deeper into sleep. Heart rate and body temperature drop. Brain waves slow down and muscles relax completely.

Then we enter the fifth stage of sleep: rapid eye movement, or REM, sleep. During this stage, our eyes dart back and forth below the eyelids, and our brain waves speed up again to the same levels as when we're awake. Most dreaming occurs during REM sleep. People need both non-REM and REM sleep in order to get a good night's rest. During a full night of sleep, we cycle through all five sleep stages between three and five times.

Scientists know that we have to sleep. Repeated experiments with lab rats have shown that rats will die from lack of sleep long before they die from lack of food. Sleep-deprived people, however, don't drop dead, but they do suffer health problems. Humans who go days without sleep begin to have digestive troubles, such as diarrhea and stomach pain. They experience memory problems and hallucinations and can quickly become paranoid.

However, scientists still aren't certain why we need to snooze. One theory is that while we sleep, our bodies repair muscles and other tissues. Some researchers believe that sleeping and dreaming are necessary for the brain to organize and store memories. Others think we slow down at night to conserve energy.

Setting Your Body Clock

Adults need about eight hours of sleep each night, but young people need even more. "Kids from about 10 to 18 need a little more than nine hours of sleep a night, on average," says Mary Carskadon, a sleep researcher and member of the NSF task force on sleep and teens. Yet Carskadon has found that most teens sleep an average of seven hours a night.

Busy schedules are only part of the problem. During adolescence, the body's internal clock gets pushed back so that a person doesn't feel sleepy until later in the evening. The result? Teens want to stay up later at night and sleep later in the morning. "I tend to be tired in the morning, and toward the end of the day I wake up," Leah says. To make matters worse, nighttime habits can also affect the body's clock. One way the body learns when to sleep is through light cues. Staying up late in a bright room or staring at a brightly lit TV or computer screen can push the internal clock back even later.

Sick and Tired

The short-term effects of too little sleep are obvious enough. Too little shut-eye can leave you feeling fuzzy-headed and unable to concentrate. "Almost all teenagers, as they reach puberty, become walking zombies because they are getting far too little sleep," says Cornell University psychologist James Maas in the American Psychological Association's Monitor on Psychology. Over time, skimping on sleep can cause a sleep debt to accumulate, and that can have serious consequences. "As the sleep deficit goes on week after week, your body changes," Carskadon adds.

Sleep-deprived people have problems with learning and memory. Mood is also affected, and overtired teens can show mood problems that mimic depression. In some cases, youths may be prescribed medication for depression when, in fact, they're just way behind on sleep. Also, the hormone cortisol, which is associated with stress, can build up in the sleep-deprived. High cortisol levels weaken the immune system, making a person more susceptible to illness.

New studies are also revealing that sleep debt can mess with metabolism, the chemical processes that occur within an organism to sustain life. "If you aren't getting enough sleep, you're likely to eat more and also process food differently," Carskadon reports. Those metabolic changes can lead to weight gain and related health problems, including diabetes.

Unfortunately, sleep debt is hard to overcome. Sleeping in on weekends is your body's way of playing catch-up-but if you overdo it, you could be making matters worse. Carskadon suggests sleeping for an extra hour or two, but not all day. Your body will thank you for it Monday morning, she says.

Still, it's important to listen to your body and give it the rest it craves. "Kids need to be happier," says Carskadon. "I think if they had more sleep, they'd be happier." CH2

IMAGE ILLUSTRATIONSIDEBAR

'Almost all teenagers, as they reach puberty, become walking zombies because they are getting far too little sleep.'

Insomnia occurs when a person can't fall asleep or awakens too early. If you have trouble sleeping on a regular basis, these tips could help you get some shut-eye:

Keep your bedroom dark at night and bright in the morning, since light cues help set your body's internal clock.
Exercise during the day, no fewer than three hours before bedtime.
Avoid big meals at night; eat dinner at least two hours before going to bed.
Don't drink caffeine after lunchtime.
Have a relaxing bedtime routine.
Go to bed at the same time every night to train your body when to sleep.
Are you staring at the clock and worrying that you aren't getting a good night's sleep? Turn the clock toward the wall and relax.
If you can't fall asleep, get out of bed. Teach your body that your bed is for sleeping.
Think positive thoughts. Instead of thinking "I'm going to be so tired tomorrow/," try telling yourself "I'm probably getting more rest than I realize."
Don't sleep in all day on weekends-it will confuse your body's clock. If you feel you need to catch up on sleep, take a 30- to 40-minute nap during the day.

IMAGE PHOTOGRAPH

While this boy sleeps, technicians at the sleep lab study his brain activity!

SIDEBAR

Sleep Disorders

Most tired teens simply don't get the sleep they need. But some suffer from medical conditions that interfere with sleep. One of the most common conditions is obstructive sleep apnea. This condition causes a person to stop breathing for 10 to 20 seconds during sleep. A person with sleep apnea often stops breathing for a few seconds several times each night, waking repeatedly; this condition makes restful sleep impossible. Obesity can be a risk factor for sleep apnea, because excess tissue in the throat can block airways. But genetics and skull structure can also contribute to the disorder, and anyone-male or female, young or old-can be affected.

If you think you might be suffering from sleep apnea, visit your doctor. He or she might have you spend the night in a sleep clinic, where physicians will monitor you while you sleep. If they determine that apnea is affecting you, they may treat it with medications or with a mechanical device that you can wear while you sleep.

didja know?

IMAGE PHOTOGRAPHSIDEBAR

dreams

Reptiles sleep, but they don't dream. Birds sleep and dream a little bit. All mammals dream during sleep.

Science > Life Sciences (Biology) > Neurobiology > Central Systems > Sleep & Biological Rhythms > Basics

Science > Life Sciences (Biology) > Neurobiology > Central Systems > Sleep & Biological Rhythms > Mechanisms of Sleep & Waking

Science > Life Sciences (Biology) > Neurobiology > Central Systems > Sleep & Biological Rhythms > Sleep Disorders

Volume: 32

Start Page: 16

ISSN: 0163156X

Date: 10-01-2005

Size: 8 Kb

CRL #: 10

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