The Toll of Sleep Loss in America
Sleep loss is taking a toll on our physical and emotional health, and on our nation's highways.
The Effects of Lost Sleep continued...
If you're getting less sleep than your body needs, there can be serious consequences.
"There's recent evidence showing -- in men and women in several countries -- that chronic sleep deprivation increases risk of early death," Hunt tells WebMD. "Studies are showing that people who get less sleep are at greater risk for heart disease and heart attacks. And perhaps the hottest area of research has shown a link between chronic sleep deprivation and risk of overweight and obesity. These studies articulate the price society pays in not getting a good night's sleep."
The affect on our functional status was borne out in the 2005 Sleep in America survey. Over one-quarter of working adults - 28% -- said they had missed work, events and activities, or made errors at work because of sleep-related issues in the previous three months.
Laboratory studies have confirmed this impact on performance. In one small experiment, 16 young adults were allowed only five hours of sleep for seven nights. As the week wore on, the volunteers showed increasing difficulty performing tasks.
It's true, some people can get by just fine with less sleep. One study found that there are significant differences in impairment among sleep deprived volunteers - suggesting that vulnerability to sleep deficits varies greatly.
But for most people, getting less than six hours sleep translates into a bigger sleep debt than they may realize. Over a two-week period, missing out on the recommended eight hours of nightly sleep adds up to two full nights' sleep debt, one study found. If you're averaging only four hours a night, your brain reacts as though you haven't slept at all for three consecutive nights.
The most worrisome part: Many people are too tired to realize how sleep-deprived they are, experts say. But they have slower reaction time, weaker memory, and other thinking impairments.
The Dangers of Drowsiness
Sleep-deprived people often don't realize their vulnerability to sleepiness, and therein rests the self-denial, explains Joseph Kaplan, MD, co-director of the Sleep Disorders Center at the Mayo Clinic in Jacksonville, Fla.
"Sleepiness is governed by two processes - the amount of sleep you get and the circadian rhythm," he tells WebMD. "You can go a night without sleep, and be fairly alert the next morning. But as the circadian influence begins to have its impact, that's when you really feel it."
Kaplan says the most vulnerable times for sleepiness: 5 to 8 a.m. and 2 to 4 p.m. Most alert times: 10 a.m. to noon and 7 to 9 p.m. "Regardless how many hours you're awake, the sleepiest time occurs as the circadian night is ending," he says.
Night shift workers may be the hardest hit by sleep problems. They're less able to stay alert, they have decreased job performance, and they have more accidents. One study found that 20% of shift workers fall asleep during a single night shift compared to none during an afternoon or evening shift.