How much sleep do we need?

While the exact role of sleep remains something of a mystery, there's no mystery to how we feel during the day if we're shortchanged on sleep. According to the National Institutes of Health, experts say that if you start feeling drowsy during the day, you're probably short on sleep. While you might like it if you fall asleep within a few minutes of going to bed, it's likely a sign you're sleep deprived.

And if you're driving or operating equipment, sleep deprivation can be dangerous.

Yet the amount of sleep any of us needs depends on our age, genetics and environment. The oft-quoted "experts" say eight hours is about right. That, says one group of researchers, may worry folks who routinely get six or seven hours a night, even though that's now about average.

In fact, that research team, from the University of California, San Diego, and the American Cancer Society, recently reported a study that found that people who got only 6 or 7 hours of sleep a night had a lower death rate than those who slept 8 hours or more -- or 4 hours or less. The research looked at data from more than a million people participating in a cancer prevention study.

What the connection might be isn't clear, but the study suggests, as one of the scientists put it, people who average six-and-a-half hours of sleep "can be reassured this is a safe amount of sleep."

Resources
The National Sleep Foundation

National Center on Sleep Disorder Research, part of the NIH

April 13, 2002

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