Sleep plays a tremendous role in health and overall quality of life. Sleep is vitally important for feeling refreshed and rejuvenated in the morning, feeling energetic during the day, developing memory, learning, determining mood, maintaining concentration, supporting the body's immune system, and more. Most adults need an average of about 7-8 hours of quality sleep per night. Proper sleep habits, also known as sleep hygiene, constitute a major part of preventive health.

Individuals' sleep habits naturally vary with respect to timing and duration. Some people are more active and alert in the morning ("morning larks") while others are more wakeful at night ("night owls"). Some people need more or less sleep than the typical 7-8 hour recommendation. But all people require adequate quality sleep to function at their fullest and to prevent the serious consequences associated with sleep problems (see below).

Two additional resources for further information about sleep are the National Sleep Foundation (http://www.sleepfoundation.org/) and the American Academy of Sleep Medicine (http://yoursleep.aasmnet.org/).

Healthy Sleep
Explore our Healthy Sleep topics to learn more about the importance of sleep and how sleep works. A few notes about healthy sleep:

• Children and infants have very different sleep patterns and require more sleep than adults. See http://www.sleepfoundation.org/article/sleep-topics/children-and-sleep for more information.
• Adolescents generally require more sleep than adults. In addition, they tend to get sleepy later at night, and tend to wake up later in the morning. See http://www.sleepfoundation.org/article/hot-topics/adolescent-sleep-needs-and-patterns for more information.
• Older individuals and elderly tend to get sleepy earlier in the evening, and tend to wake up earlier in the morning. Sleep problems are very common in older individuals. See http://www.sleepfoundation.org/article/sleep-topics/aging-and-sleep for more information.
• Circadian rhythms refer to the daily cycle of sleepiness and wakefulness. Light, environmental cues, genetic makeup, ambient temperature, meals, and exercise all affect daily sleepiness and wakefulness patterns.
• Napping can be beneficial for overall health. Natural circadian rhythms often produce feelings of sleepiness in the mid-afternoon, and naps during this time are common.

Unfortunately, many people do not get healthy or adequate sleep, with sleep-related problems affecting 50-70 million Americans. Sleep problems are associated with obesity, high blood pressure, diabetes, stroke, heart attack, motor vehicle accidents, work-related accidents, stress, depression, poor attention, reduced memory, and more. Sleepy drivers are responsible for over 100,000 automobile accidents per year and this leads to over 70,000 injuries and over 1,500 deaths. Sleep deprivation also decreases work productivity. Sleep disruption may be caused by worry, poor sleep habits, medical or mental illness, jet lag, noises, sleep disorders, and many other environmental factors.

For most people, ways to improve sleep include:

• Avoiding caffeine and other stimulants after lunch
• Exercising early or mid-day and avoiding heavy exercise at night
• Avoiding large meals close to bedtime
• Getting enough bright light exposure during the day
• Keeping the bedroom environment very dark at night
• Establishing regular bedtime routine
• Avoiding stimulating activities such as: TV, radio, reading, computers, and more at bedtime
• Keeping the sleep environment calm and comfortable
• Establishing regular bedtime and wake time

Sleep Problems
A number of sleep disorders exist that can negatively affect sleep and overall health. These problems include insomnia, narcolepsy, sleep apnea, and more. Explore our Sleep Problems topics to learn more about specific sleep disorders and the consequences of poor sleep.

For healthy individuals, maintaining proper sleep hygiene is an achievable aspect of preventive health that offers great benefits to long-term health and quality of life. For people with specific sleep disorders or other conditions disrupting sleep, the underlying problems can be evaluated and treated.