It may seem obvious that sleep is beneficial. Even without fully grasping what sleep does for us, we know that going without sleep for too long makes us feel terrible, and that getting a good night's sleep can make us feel ready to take on the world.
Scientists have gone to great lengths to fully understand sleep's benefits. In studies of humans and other animals, they have discovered that sleep plays a critical role in immune function, metabolism, memory, learning, and other vital functions.
Sleep is essential to good health. It's one of the body's basic needs. Most people realize that if you're under stress, you don't sleep well. But I'm not sure people fully understand the deeper connections. When you don't sleep well, your ability to concentrate, to calmly deal with daily pressures, to simply feel good is compromised.
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.