What Are Sleep and Wakefulness?
Sleep is an important part of overall health and quality of life. How well you sleep greatly affects how well
you feel when you are awake.
Both length and quality of sleep are important for good health.
Most people spend nearly a third of their lives sleeping. That time is necessary for productivity and health.
What Are the Benefits of Sleep?
Sleep is important because the body uses this time to replenish and repair itself. It needs this time to repair muscles, consolidate memories, and release hormones that maintain growth and digestion. Quality sleep helps control appetite and support immunity.
Too little or too much sleep can cause health problems, decrease quality of life, and lead to shortened life
The length of desired sleep time depends on age. Children and teens need more sleep than adults. For adults, seven to nine hours of sleep is generally considered appropriate. Less than seven or more than 10 hours per night can be problematic. Many adults are chronically sleep deprived from going to bed too late or waking up too early. Sleep shortage can leave a person feeling fatigued, unable to concentrate, and mentally foggy.
Stages of Sleep
The sleep cycle can be broken down into NREM and REM stages.
NREM (non-rapid eye movement) makes up 75 percent of sleep time, and REM (rapid eye movement) makes up about 25 percent. An REM stage occurs approximately every 90 minutes during sleep time.
There are four NREM stages:
- Stage 1 occurs when a person has
just gone to bed and is in transition between wakefulness and sleep.
- Stage 2 occurs when a person falls
asleep and becomes unaware of their surroundings. The body temperature drops
and breathing and heart rates fall into a natural rhythm.
- Stage 3 and 4 occur during deep
sleep. Breathing slows, blood pressure decreases, and the muscles become
completely relaxed. This type of sleep is more restorative. Blood to the
muscles increases, growth hormones are released, and tissues can repair
During REM cycles, the brain is targeted. This type of sleep energizes the body and brain and helps you be alert and focused during the day. During REM sleep, the eyes move around, the brain is active, and the body is relaxed. This is when dreams occur.
Some people have sleep disorders that make it difficult to get quality sleep. Sleep disorders include insomnia, sleep apnea, circadian rhythm disorders, and parasomnias.
Insomnia is a common condition. It is characterized by difficulty falling asleep, often due to an overactive brain.
Stress, worry, too much light, and inconsistent sleep schedules can make insomnia worse.
Sleep apnea occurs when the airways briefly collapse, halting breathing. This often wakes the person suddenly and causes stress, resulting in poor sleep.
Circadian rhythm disorders occur when sleep schedules become irregular. Jet lag can cause sleeping difficulties. The most common type of circadian rhythm sleep disorder is called shift work disorder. People who work during the night are most at risk of shift work disorder. It occurs when a person feels tired at night while working but has difficulty sleeping during the day when not working.
Parasomnias include sleepwalking, talking during sleep, teeth grinding, nightmares, and wetting the bed. These behaviors can influence the stages of sleep, resulting in poor quality sleep.
Many sleep disorders can be treated through lifestyle changes. These include changes to the sleep environment such as dampening light and removing distractions, as well as practices such as practicing meditation. Some sleep disorders require medication. Sleep apnea can be helped with a CPAP machine, a ventilator that helps keep airways open.
Tips for Sleeping Well
Sleeping well is necessary for good health, but for many people it is hard to do.
At home, it can help to make the bedroom more sleep-appropriate, by keeping it dark, cool, and quiet. Other
ideas include limiting lighting, buying dark curtains, and using earplugs.
Developing a pre-sleep routine can also help prepare the body and mind for sleep. This can include relaxing, taking a warm bath, reading, listening to calming music, drinking herbal tea, writing in a journal, practicing restorative yoga, or meditating. Avoiding bright lights, loud noises, and computer screens before sleep is often recommended.
A consistent sleep schedule, in which sleep and wake up times are kept constant, can also help.
Because stress is often a cause of sleep deprivation, efforts to reduce stress are important. For example, consider simplifying your lifestyle, setting priorities, delegating, and taking breaks.
Other tips to improve sleep quality:
- Avoid caffeine, especially late in
- Avoid alcohol, which can disrupt
- Eat regular, healthy meals.
- Limit nighttime beverages to lessen
the need for bathroom trips.
- Avoid late-day exercise.
- Practice yoga or meditation.
- Avoid daytime naps or limit them to
- Avoid using electronics and
telephones before bed.
- Avoid watching television while
lying in bed.