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NIH MedlinePlus the Magazine, Trusted Health Information from the National Institutes of Health

Are You Sleep-Deprived?

The Importance of Sleep

Man counting sheepMany people view sleep as merely a "down time," when their brains shut off and their bodies rest. People may cut back on sleep, thinking it won't be a problem, because other responsibilities seem much more important. But research shows that a number of vital tasks carried out during sleep help people stay healthy and function at their best.

While you sleep, your brain is hard at work forming the pathways necessary for learning and creating memories and new insights. Without enough sleep, you can't focus and pay attention or respond quickly. A lack of sleep may even cause mood problems. Growing evidence shows that a chronic lack of sleep can also increase your risk of obesity, diabetes, cardiovascular disease, and infections.

Despite growing support for the idea that adequate sleep, like adequate nutrition and physical activity, is vital to our well-being, people are sleeping less. The nonstop "24/7" nature of the world today encourages longer or nighttime work hours and offers continual access to entertainment and other activities. To keep up, people cut back on sleep.

A common myth is that people can learn to get by on little sleep (such as less than six hours a night) with no negative effects. Research suggests, however, that adults need at least seven to eight hours of sleep each night to be well rested. Indeed, in 1910, most people slept nine hours a night. Recent national surveys show that 30 percent of U.S. adults sleep fewer than seven hours a night. As many as 30 percent of adults also report daytime sleepiness so severe that it interferes with work, driving, and social functioning at least a few days each month.

Evidence from other national surveys indicate that 70 percent of adolescents sleep less than the recommended 8 to 9 hours each night. Lack of sleep may have a direct effect on children's health, behavior, and development.

Summer 2012 Issue: Volume 7 Number 2 Page 17