How Much Do We Need?
Changing NeedsDuring the first year of life, humans sleep more than they do anything else. Infants get about 16 hours of sleep per day, on average. They spend about half of that time in REM sleep, the brain's busiest sleep phase. As kids enter the toddler years, they still need more sleep than adults—about 11 hours per night. They are growing, learning, and processing what they learn, and their bodies and brains need adequate sleep time to get it all done. Once children begin school, they need about 9 hours per night. School-age kids may resist bedtime, or wake during the night, resulting in less sleep. The consequences could affect them at school. In a 2009 Finnish study children age 7 to 8 years who average 7.7 hours or less of sleep had more behavior problems than those who slept more. In another study, conducted in 2010 at Sarnoff Research Institute, kids with good sleep habits exhibited better language and listening skills, and early math and literacy abilities. READ MORE
From the teen years on, most people should aim for 8 hours of sleep per night. However, sleep research shows that teens have a shift forward in their natural sleep/wake cycle resulting from changes in their melatonin production. Most teens will naturally be more alert later at night, and function better if they can sleep a bit later in the morning. Some high schools in Minnesota and Massachusetts have experimented with later start times to allow night-owl teens time to get more sleep in the morning. The results have been positive. Being more alert at school has resulted in fewer discipline problems, less tardiness, and more efficient work habits during school hours (which means less homework at night).
Most adults should feel refreshed and function well if they get between 7 and 9 hours of sleep per night. Contrary to popular belief, those over 70 do not need less sleep. They simply tend to get less sleep. In adulthood and the senior years, more than one-third of the U.S. population reports inadequate or disrupted sleep. Many health issues, stress, chronic pain and other factors can be at the root of adults' sleep loss. Figuring out the problem and taking steps to get healthful sleep is vitally important. LESS
Short SleepersYou may know someone who swears he functions just fine on 4 or 5 hours of sleep per night. Researchers say that a small minority of adults—no more than 3%--get by on much less sleep than the recommended average, but suffer no ill consequences. Many more adults sleep less than 6 hours per night and consider themselves natural short sleepers. But most of those people are actually sleep-deprived and at risk of health complications, the experts say. Many also nod off during the day for naps or microsleeps, sometimes unaware that they are conking out. Sleep scientists at the University of California-San Francisco and the University of Utah are studying short sleepers to see if there is a genetic clue to their increased hours of alertness. READ MORE
Do you think you may be a natural short sleeper? Here's the acid test: When you can sleep later, on vacation or the weekends, do you still sleep your usual amount of hours, or do you sleep more? Those who sleep more when they can are not true short sleepers. LESS
Narcoleptics fall asleep off-cycle, often at several times throughout the day. Symptoms can include a slackening of the muscles called cataplexy, hallucinations, and sleep paralysis. Narcoleptics are plunged into REM sleep without going through the non-REM stages first. Many narcoleptics are found to have a deficiency in hypocretin, and protein created in the brain's hypothalamus. Hypocretin helps regulate alertness, and REM sleep. There is no cure for narcolepsy, but doctors can help regulate alertness with stimulants and other medications to normalize narcoleptics' sleep cycles. READ MORE
These actions that occur during sleep, such as nightmares or sleep-talking, most often happen during N3 or slow-wave sleep. Sleepers who experience night terrors, bedwetting, sleepwalking, or sleep talking may wake during these events, and have to start their sleep cycle over. Many parasomnias are common, and experienced in periods of stress or growth. Those whose parasomnia events take them out of bed can be in danger, as they are still in not conscious while walking. If you or someone in your family is a sleep walker, take precautions to limit their traveling range. LESS