Why Sleep Is Important
Sleep Is a Basic Human Need
Sleep is a natural part of everybody's life, but many people know very little about how important it is, and some even try to get by with little sleep. Sleep is something our bodies need to do; it is not an option. Even though the exact reasons for sleep remain a mystery, we do know that during sleep many of the body's major organ and regulatory systems continue to work actively. Some parts of the brain actually increase their activity dramatically, and the body produces more of certain hormones.
Sleep, like diet and exercise, is important for our minds and bodies to function normally. In fact, sleep appears to be required for survival. Rats deprived of sleep die within two to three weeks, a time frame similar to death due to starvation.
An internal biological clock regulates the timing for sleep. It programs each person to feel sleepy during the nighttime hours and to be active during the daylight hours. Light is the cue that synchronizes the biological clock to the 24-hour cycle of day and night.
Problem Sleepiness Has Serious Consequences
Sleepiness due to chronic lack of adequate sleep is a big problem in the United States and affects many children as well as adults. Children and even adolescents need at least 9 hours of sleep each night to do their best. Most adults need approximately 8 hours of sleep each night.
When we get less sleep (even one hour less) than we need each night, we develop a "sleep debt." If the sleep debt becomes too great, it can lead to problem sleepiness – sleepiness that occurs when you should be awake and alert, that interferes with daily routine and activities, and reduces your ability to function. Even if you do not feel sleepy, the sleep debt can have a powerful negative effect on your daytime performance, thinking, and mood, and cause you to fall asleep at inappropriate and even dangerous times.
Problem sleepiness has serious consequences – it puts adolescents and adults at risk for drowsy driving or workplace accidents. In children, it increases the risk of accidents and injuries. In addition, lack of sleep can have a negative effect on children's performance in school, on the playground, in extracurricular activities, and in social relationships.
Inadequate sleep can cause decreases in:
- Reaction Times
- Consolidation of Information Learning
Inadequate sleep can cause increases in:
- Memory Lapses
- Accidents and Injuries
- Behavior Problems
- Mood Problems
Signs of Sleep Disorders
A child who has not obtained adequate nighttime sleep is at high risk for symptoms of physical and/or mental impairment. The child may fall asleep in school, have difficulty concentrating in school and other activities, and/or exhibit behavioral problems. Some children who are sleepy become agitated rather than lethargic and may be misdiagnosed as hyperactive. Not getting enough sleep is one cause of problem sleepiness. Undiagnosed/untreated sleep disorders can also cause problem sleepiness. Children as well as adults can suffer from sleep disorders. Parents should talk to their pediatrician about a possible sleep disorder if their child has any of the following:
- Breathing Pauses During Sleep
- Problems with Sleeping at Night
- Difficulty Staying Awake During the Day
- Unexplained Decrease in Daytime Performance
Reprinted with the permission of the National Institute of Mental Health. © 2008 NIMH.