About Sleep and Sleep Disorders
The National Sleep Foundation found that 74 percent of American adults experience a sleep problem a few nights a week or more. Thirty-nine percent get less than seven hours of sleep each weeknight, and more than 37 percent experience daytime sleepiness that interferes with daily activities.
Insomnia is a sleep problem experienced by over 50 percent of Americans who report difficulty falling asleep, frequent awakenings, waking too early and having trouble getting back to sleep, and waking unrefreshed. Insomnia can be short-or long-term in nature and may be due to stress, an underlying medical or psychiatric problem such as depression, a loss, poor sleep, or health habits.
Sleep apnea sufferers actually stop breathing for several seconds, waking up hundreds of times per night snorting and gasping for air. Sleep apnea is most common in men and people who are overweight. Untreated, it can result in high blood pressure and an increased risk of heart attack or stroke.
People with narcolepsy experience "sleep attacks" which can occur at any time. Strong emotions sometimes bring on cataplexy, a sudden loss of muscle control. When falling asleep or waking up, sufferers may also experience brief paralysis and/or vivid images and sounds.
Restless Legs Syndrome
Those with restless legs syndrome have unusual sensations in the legs and sometimes arms that disturb sleep. Only movement brings relief. Individuals may also experience periodic limb movement disorder, or jerking of the legs during sleep.
Parasomnias are disruptive sleep-related disorders that include nightmares, night terrors, sleepwalking, confused arousals, and many others. Nightmares are vivid nocturnal events that can cause feelings of fear, terror, and/or anxiety. A person experiencing a night terror or sleep terror abruptly awakes from sleep in a terrified state. Sleepwalking, a tendency to get up and wander about while asleep, is most common in children and tends to run in families.
Sleep Quantity and Quality Count
Getting enough continuous quality sleep contributes to how we feel and perform the next day. It also has a huge impact on the overall quality of our lives.
Sleep requirements vary over the life cycle. Newborns and infants need a lot of sleep and have several periods of sleep throughout a 24-hour time period. Naps are important to them, as well as to toddlers, who may nap up to the age of five. As children enter adolescence, their sleep patterns shift to a later sleep-wake cycle, but they still need around nine hours of sleep. Although sleep experts generally recommend adults get an average of seven to nine hours per night, some people can get along with less, while others need as much as 10 hours.
Planning and allowing enough time to sleep is essential to a person’s overall well-being and quality of life. This includes allotting time to awaken naturally—without an alarm clock. Not getting enough sleep leads to poor performance at work, increased risk for injury, poor health, and difficulty getting along with others. People often become irritable due to lack of sleep, which can result in serious consequences. Studies show that lack of sleep leads to problems completing tasks, concentrating, and making decisions.
Recent research suggests that sleep deprivation impacts aging and diabetes. Insufficient sleep may also make it difficult to exercise and can reduce the benefit of hormones released during sleep. Just as compelling are the serious consequences of sleep deprivation that lead to approximately 100,000 sleep-related vehicle crashes each year resulting in 1,500 deaths.
The Importance of Nighttime Sleep
Two brain processes regulate sleep. One is the restorative process when sleep occurs naturally in response to how long we are awake—the longer we are awake, the stronger is the drive to sleep. The second process controls timing of sleep and wakefulness during the day-night cycle.
Timing is regulated by the circadian biological clock that is located in our brain. This part of the brain, the suprachiasmatic nucleus, is influenced by light. We naturally tend to get sleepy when it is dark at night and be active when it is light during the day. In addition to timing the sleep-wake cycle, the circadian clock regulates day-night cycles of most body functions, ensuring that the appropriate levels occur at night. For example, important hormones are secreted, blood pressure is lowered, and kidney functions change.
Research indicates that memory is consolidated during sleep. This “clock” in the brain runs on a 24-hour cycle. We feel most sleepy around 2 to 4 a.m., and in the afternoon between 1 and 3 p.m. We need to have continuous, restorative sleep to feel refreshed and alert for the day ahead.
Quality of Sleep
Quality sleep is continuous and uninterrupted. As we get older, sleep can be disrupted due to pain or discomfort, the need to go to the bathroom, medical problems, medications, and sleep disorders, as well as poor or irregular sleep schedules.
Establishing a regular bed and wake schedule helps a person achieve continuous sleep in accordance with his or her internal biological circadian clock, and experience the sleep stages necessary to reap its restorative, energizing, and revitalizing benefits.
States and Stages of Sleep
As we sleep, we pass through different states and stages of sleep. These are more likely to be experienced with continuous sleep. This "sleep architecture" follows a predictable pattern of rapid-eye movement (REM) and non-rapid eye movement (NREM) sleep throughout a typical eight-hour period.
Both REM and NREM states are important to experiencing quality sleep. These states alternate every 90 minutes. Time spent in these states and stages of sleep varies by age.
NREM lasts 75 percent of the night. As we begin to fall asleep, we enter NREM, composed of four stages:
- Stage 1 - Light sleep; between being awake and entering sleep
- Stage 2 - Onset of sleep; disengaging from the environment; breathing and heart rate are regular, and body temperature goes down
- Stage 3 and 4 - Deepest and most restorative sleep; blood pressure drops; breathing is slowed; energy is regained, and hormones are released for growth and development
REM sleep takes up 25 percent of the night. REM sleep:
- First occurs about 90 minutes after falling asleep and increases later in the night
- Provides energy to the brain and body
- Activates the brain; dreams occur as the eyes dart back and forth
- Immobilizes and relaxes the body
- Shuts down muscles
During REM, breathing and heart rate may become irregular. REM sleep is important for daytime performance and may contribute to memory consolidation.
Tips for Quality Sleep
- Avoid caffeine and nicotine close to bedtime
- Avoid alcohol, as it can lead to disrupted sleep
- Exercise regularly, but complete your workout at least three hours before bedtime
- Establish a regular, relaxing bedtime routine (e.g., taking a warm bath or shower)
- Create a sleep-conducive environment that is dark, quiet, and preferably cool and comfortable
- Use a sleep diary to examine sleep habits
The Perils of Shift Work
With around-the-clock activities, our 24/7 society can keep us from allocating enough time for sleep or put us on irregular schedules. Feeling sleepy is a common experience, particularly for over 20 million American shift workers. The body never adjusts to shift work, and nontraditional schedules put employees at risk for on-the-job accidents and car crashes.
As many Americans travel across time zones, they also experience jet lag, which puts them in conflict with their natural sleep patterns. The shift in time and light forces the brain and body to alter from its normal pattern and adjust to the new time zone.
Circadian Rhythm Disorders
The complex biological “clock” in humans sometimes breaks down. In delayed-sleep phase syndrome, the clock runs later than normal. The sufferer often cannot fall asleep before 3 or 4 a.m. and cannot wake before noon. In advanced-sleep phase syndrome, a person falls asleep early, for example at 7:00 p.m. or 8:00 p.m. and wakes at 3:00 a.m. or 4 a.m., unable to fall back asleep.
Learn more about MVH Sleep Center.