What is a sleep disorder?


A sleep disorder interferes with one's ability to sleep normally. For many people, it is a chronic, nightly problem that can affect daytime behavior. Activities at work and school and relations with loved ones can be affected. A sleep disorder can worsen existing medical conditions, and it can also lead to new medical problems.


What are the most common sleep disorders?


There are over 85 known sleep disorders.

Those most commonly seen include:


1. Circadian Rhythm Disorders

2. Excessive Sleepiness

3. Insomnia

4. Narcolepsy

5. Obstructive Sleep Apnea

6. Parasomnias

7. Periodic Limb Movement Disorder

8. Restless Legs Syndrome

9. Snoring



1. Circadian Sleep Disorders


Circadian sleep disorders are disorders of the timing of sleep and wakefulness. We all have an internal "clock," which controls our rhythm of sleeping and wakefulness. There are times of the day when we are most alert -- most often mid-morning and early evening. And, there are times when we are more likely to be sleepy – early to mid-afternoon and late evening. Our environment impacts this rhythm, and may either complement or disrupt our internal clock.


Excessive sleepiness can develop when our sleep rhythm is altered. We may feel sleepy when we need to remain awake. On the other hand, insomnia is when we don't feel sleepy when we do want to sleep,


Disorders that are related to changes in the normal sleep-wake pattern:


Advanced Sleep-Phase is a shift in nighttime sleep to a time earlier than the desired bedtime. Arising time the next morning is also earlier than desired. Bedtime often occurs between 6 p.m. and 9 p.m. Arising time often occurs between 1 a.m. and 3 a.m.


Delayed Sleep-Phase is when the usual nighttime sleep period occurs later than the desired bedtime. These "night owls" are unable to sleep until the early morning hours. They don't arise until late morning to early afternoon.


Irregular Sleep-Wake Pattern  The timing of sleep and wake activities are erratic. Three or more naps replace the major nighttime sleep. Evening insomnia and daytime sleepiness are common symptoms.


Jet Lag  After rapid travel across many time zones, our internal clock remains fixed to our home time zone. It may take a few days for the internal clock to adjust to the new time zone. For example, the advanced bedtime after an eastward flight may result in trouble falling asleep at a "normal time." On the other hand, westward flights result in a delay in nighttime sleep. It also results in increased awakenings during the early morning hours. Luckily for the traveler, sleep tends to improve after two to three days.


Shift Work Sleep Disorder  Large numbers of people in this country perform shift work. Excessive sleepiness and insomnia may develop when people work outside the 8 a.m. to 5 p.m. shift. Sleepiness and decreased concentration is common if one must work at night. A shift work sleep disorder poses a major hazard in the workplace.

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2. Excessive Sleepiness


Chronic lack of sleep is a common cause of excessive sleepiness. It is important to get enough sleep. Getting enough sleep each night will help you maintain normal alertness and performance while awake.


A person may allow plenty of time for sleep, but sleep time can be interrupted by sleep apnea or periodic limb movements . Excessive sleepiness occurs with sleep disorders such as narcolepsy, or circadian rhythm disorders, which is a simple disturbance of the body clock. This occurs because the timing of wakefulness and sleep is altered. Two examples are jet lag or shift work.


Medicines can cause excessive sleepiness. Medicines that sedate as a side-effect can cause this. The routine use of sedating or opioid pain medicines may also cause excessive sleepiness. This is more likely to occur if large doses or long-acting medicines are taken during the night. Excessive sleepiness may occur if stimulant medicines are quickly stopped. Speak to your doctor if you are concerned that your medicines may be causing excessive sleepiness.


Why should I worry about feeling tired during my day?


Excessive sleepiness becomes a problem when the person cannot stay awake and alert long enough to complete daily tasks. Sleep occurs during the day. Excessive sleepiness is different from fatigue or physical tiredness.


Excessive sleepiness may increase the risk of car, work, or home accidents. It may also cause poor school or work performance. Memory problems and changes in behavior can also occur.


Are some types of excessive sleepiness worse than others?


Mild sleepiness occurs during rest, or when little attention is required for the activity. Examples including reading or watching television.


Moderate sleepiness is present if it occurs during activities that require more attention. They may be physical or mental. One example is during a group meeting.


Severe sleepiness occurs during physical activities, which require full attention. Examples include talking, eating, or driving.

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3. Insomnia


Insomnia is the failure to fall asleep and/or remain asleep.  Sleep is light and easily disturbed.  Other common symptoms include:


* fatigue

* irritability

* poor attention


Insomnia can increase the chance of accidents, decrease performance, and impair judgment.


Are some types of insomnia more severe than others?


Mild Insomnia:  Poor sleep has little effect on social function or work.


Moderate Insomnia:  Poor sleep impacts social and work function.


Severe Insomnia:  Poor sleep has a major impact on how a person functions during the day.


Acute Insomnia:  Poor sleep lasts only a few days.


Chronic Insomnia:  Poor sleep may last for several months or more. It may start in early childhood and be life-long.


What causes insomnia?


There are many reasons for poor sleep. Often there is more than one cause. Causes and types of insomnia may include:


Acute stress - Acute stress, such as major life events (tragic loss, marriage, a job change, or an exam) can lead to insomnia. Sleeping in new settings such as a hotel or hospital room can also lead to insomnia. This type of sleep disturbance is brief. Sleep tends to return to normal once the stress is removed or reduced, or when the person learns to cope with it.


Bedtime Behavior in Children - Children often attempt to delay bedtime. A child may ask for one more bedtime stories, take several trips to the bathroom, ask for food or water, or to watch a few more minutes of television. These attempts to delay the bedtime should be recognized by the caretaker, and then limited before bedtime. Once this is accomplished, sleep often occurs naturally and quickly.


However, several other factors may also affect a child's sleep. These include fear of the dark, fear of being left alone, or an unreasonably early bedtime. Some children are unable to sleep unless a special blanket or pacifier is present.


Environmental Factors - Loud noise, bad odors, bright lights, and extremes in room temperature can disturb sleep. A snoring sleep partner or an uncomfortable bed can also disturb sleep. Concerns about safety in the house and caring for a family member may also cause poor sleep. Altitude can affect sleep, and sleep disturbance can develop after a rapid ascent to a high altitude.


Medical Conditions - Some medical conditions may cause insomnia. If you have a chronic illness and you are having sleep disturbances, talk with your doctor.


Medicine-induced Insomnia - Medications can be a major cause of insomnia. Stopping medicine that encourages sleep after long-term use can lead to severe insomnia. Some medicines have a stimulating effect. They cause wakefulness and alertness. These can cause insomnia, often when taken close to bedtime, or when the dose is increased. I fyou take any of these medicines and are having sleep disruptions talk with your doctor. Do not stop any medicines if you have not consulted with your doctor.


Poor Sleep Hygiene - Insomnia can begin with habits or activities that do not promote sleep. Caffeine, alcohol, or smoking too close to bedtime can lead to poor sleep. Strenuous exercise or stimulating mental activity can as well. Frequent changes in bedtime or awakening times can disrupt sleep. Napping during the day can also disrupt sleep. Performing activities in bed such as doing homework, talking on the telephone, or watching television are also habits that may cause sleep problems.


Psychophysiologic Insomnia - Behaviors that disturb sleep can develop and become the major factors causing Insomnia. For instance, an insomniac may "try too hard" to fall sleep and, therefore, become tense and even more aroused. This, in turn, increases anxiety about not being able to sleep. Thus, a vicious cycle begins.

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4. Narcolepsy


Excessive sleepiness occurs when there is a problem with the part of the brain that causes sleep and wakefulness. Narcolepsy affects 1 of every 2,000 people. Symptoms often begin in young adults, and may be hereditary. Symptoms may include:


Excessive sleepiness - This is often the first symptom of narcolepsy. It is often lifelong. Sleep occurs during moments of inactivity or boredom. Sudden and unexpected sleep "attacks" can also occur at any time. Brief napping is common. Each nap lasts 10 to 20 minutes. Sleepiness is reduced after awakening from a short nap. The sleepiness increases again within the next two to three hours.


Cataplexy - Cataplexy is the loss of muscle strength after an intense emotion. Emotions such as anger, fright, surprise, excitement, or laughter can cause this. It may occur without any cause and does not trigger loss of consciousness. Episodes may last from seconds to minutes. The loss of muscle strength may be mild, such as drooping of the eyelids, sagging of the jaw, or buckling at the knees. It may also be severe with complete lack of muscle strength causing the person to collapse.


Sleep paralysis - This is a brief loss of the ability to move. It occurs either at the start of sleep or upon awakening. Except for the eye muscles and those involved with breathing, all muscles are affected. Paralysis often lasts from one to a few minutes. Hallucinations and a sense of dread may also occur.


Sleep hallucinations - Sleep hallucinations may occur at sleep onset or upon wakening. A person may see shapes, colors, or actual figures; or, one may hear a sound or music, or feel movement. These feelings are often fearful, such as being attacked or escaping from danger.


Other symptoms of narcolepsy include disturbed sleep, waking up often, and abnormal behavior.

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5. Obstructive Sleep Apnea


Sleep apnea is a condition characterized by brief interruptions of breathing during sleep. It owes its name to a Greek word, apnea, meaning "want of breath." Sleep apnea occurs when air cannot flow into or out of the person's nose or mouth although efforts to breathe continue. In a given night, the number of involuntary breathing pauses or "apneic events" may be as high as 20 to 60 or more per hour. These breathing pauses are almost always accompanied by snoring, although not everyone who snores has this condition. Sleep apnea can also be characterized by choking sensations. The frequent interruption of deep, restorative sleep often leads to excessive daytime sleepiness and may be associated with early morning headaches. Early recognition and treatment of obstructive sleep apnea is important because it may be associated with irregular heartbeat, high blood pressure, heart attack, and stroke.


Types of apnea


There are two types of sleep apnea: central and obstructive. Obstructive Sleep Apnea (OSA) is the most common type. This is caused as the sleeper's entire body relaxes during sleep -- including the windpipe or upper airways. So, air cannot flow into or out of one's nose or mouth, although efforts to breathe continue. Breathing stops for several seconds to over a minute, and levels of blood oxygen may drop during these episodes. Each episode causes one to partially or fully awaken and then go back to sleep. Central Sleep Apnea occurs when, for some reason, the brain does not send the appropriate signals to continue breathing.


Who develops sleep apnea?


Sleep apnea tends to affect middle-age people. People with sleep apnea are often overweight. It is seen more often in men than in women. However, it can affect children and persons in a normal weight range as well.


Why is it important to find out if you have sleep apnea?


Excessive sleepiness can become so severe it impacts daily activities. You may fall asleep while driving or during meetings, formal gatherings, or church services. Your performance at school or work may decline. Many people with sleep apnea become depressed or irritable. If left untreated, sleep apnea may lead to serious medical problems. These include an irregular heart rate, heart disease, heart attack, high blood pressure, and stroke.

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6. Parasomnias


Parasomnias are physical events that occur during sleep. They may or may not disrupt sleep. Often, it is the sleep partner who calls these events to the sleeper's attention.


Confusional Arousals  Confusion and disorientation occur following arousals from sleep. This often happens in the first part of the night. There is often no memory of the event. Confusional arousals may be caused by lack of sleep. They may also be caused by abrupt awakenings from deep sleep.


Leg Cramps  A painful tightening of the muscles of the leg or foot awakens a person from sleep. Flexing or massaging the leg or foot relieves the sensation. Nighttime leg cramps are common. It may be more common among the elderly, during pregnancy, or after intense exercise.


Nightmares   Frightful dreams can quickly awaken the sleeper. Once awake, the person is fully alert. He or she can clearly remember the dream and is fearful and anxious. The person is unable to promptly return to sleep.


REM Sleep Behavior Disorder  Body movements occur with dreaming. They may be simple motions. They may also be highly complex acts such as screaming, punching, kicking, or running. These movements may result in sleep disruption and/or injury to the sleeper or sleep partner.


Rhythmic Movement Disorder  Repetitive movements of parts of the body start before falling asleep. They continue during early light sleep. This is called "head banging" if it involves motions of the head and neck. Other types include head rolling, body rolling, or body rocking. This is often seen in young children. Adolescent and adult cases are rare.


Sleep Starts   Sleep starts consist of abrupt jerks of parts of the body. These may startle a person out of sleep with a feeling of "falling" or "dreaming."


Sleep Talking  Words and sentences can be uttered during sleep. Sometimes, only unclear mumbles are heard.


Sleep Terrors   A person having a sleep terror appears to quickly awaken from sleep with profound fear. The person bolts upright from bed crying or yelling, breathing heavily with heart pounding, and with increased sweating. Unlike nightmares, people have a poor memory of these episodes and are confused. Sleep terrors occur more often in the first third of the night. They are more common in children and tend to resolve by adolescence.


Sleepwalking  The sleepwalker is difficult to arouse, may display "bizarre" behavior, and has little memory of the event. Sleepwalking can lead to physical injuries to the sleeping person. Sleepwalking is most often seen in young children. It is less common among adults.

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7. Periodic Limb Movement Disorder


Repeated body movements characterize periodic limb movement disorder. These movements may occur in the toes, feet, ankles and/or legs, during sleep. A person may be unaware of these movements during sleep, but a sleep partner may notice them. This disorder is common in older adults and in people with restless legs syndrome.

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8. Restless Legs Syndrome


Restless legs syndrome occurs when falling asleep. It is an uncomfortable feeling in the lower legs, and less often in the arms. These feelings have been described as "creeping," "crawling," or "aching." Moving the legs or walking relieves these feelings. However, they quickly recur when leg motion stops. Restless legs syndrome can make it hard for a person to fall asleep when it occurs at bedtime. It can also cause frequent awakenings during the night and then make it hard to return to sleep.


Who gets restless legs syndrome?


Five to 15% of people have restless legs syndrome. More women are affected than men. Restless legs syndrome is more common in people with anemia, kidney problems, and during pregnancy.

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9. Snoring


Snoring is as ancient as sleep itself. George Washington, Abraham Lincoln, and Theodore Roosevelt were all great men and great snorers. Snoring has, for many years, been regarded simply as a nuisance. It troubled the sleep partner more than it affected snorer. Most snorers are unaware of the disturbance they create. Descriptions have varied from a low humming to loud rumbles. Snoring may not be as harmless as it was once believed to be.


How is snoring produced?


As we sleep, the roof and walls of our mouth may vibrate as we breathe. The noise created by these vibrations may increase as the size of our throat decreases. The nose and tongue can contribute to this noise as well. The character and volume of snoring can vary across the night as well as on different nights.

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