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Friday, March 2, 2012

HƯỚNG DẪN GIÚP BẠN NGỦ NGON (YOUR GUIDE TO HEALTHY SLEEP)


COMMON SLEEP DISORDERS

A number of sleep disorders can disrupt your sleep quality and make you overly sleepy during the day, even if you spent enough time in bed to be well rested. (See “Common Signs of a Sleep Disorder”.)

More than 70 sleep disorders affect at least 40 million Americans and account for an estimated $16 billion in medical costs each year, not counting costs due to lost work time, car accidents, and other factors.

The four most common sleep disorders are insomnia, sleep apnea, restless legs syndrome, and narcolepsy. Additional sleep problems include chronic insufficient sleep, circadian rhythm abnormalities, and “parasomnias” such as sleep walking, sleep paralysis, and night terrors.


Common Signs of a Sleep disorder

Look over this list of common signs of a sleep disorder, and talk to your doctor if you have any of them on three or more nights a week:

It takes you more than 30 minutes to fall asleep at night.

You awaken frequently in the night and then have trouble falling back to sleep again.

You awaken too early in the morning.

You often don’t feel well rested despite spending 7–8 hours or more asleep at night.

You feel sleepy during the day and fall asleep within 5 minutes if you have an opportunity to nap, or you fall asleep unexpectedly or at inappropriate times during the day.

Your bed partner claims you snore loudly, snort, gasp, or make choking sounds while you sleep, or your partner notices that your breathing stops for short periods.

You have creeping, tingling, or crawling feelings in your legs that are relieved by moving or massaging them, especially in the evening and when you try to fall asleep.

You have vivid, dreamlike experiences while falling asleep or dozing.

You have episodes of sudden muscle weakness when you are angry or fearful, or when you laugh.

You feel as though you cannot move when you first wake up.

Your bed partner notes that your legs or arms jerk often during sleep.

You regularly need to use stimulants to stay awake during the day.

Also keep in mind that, although children can show some of these signs of a sleep disorder, they often do not show signs of excessive daytime sleepiness. Instead, they may seem overactive and have difficulty focusing and concentrating. They also may not do their best in school.


Insomnia

Insomnia is defined as having trouble falling asleep or staying asleep, or as having unrefreshing sleep despite having ample opportunity to sleep. Life is filled with events that occasionally cause insomnia for a short time. Such temporary insomnia is common and is often brought on by situations such as stress at work, family pressures, or a traumatic event. A National Sleep Foundation poll of adults in the United States found that close to half of the respondents reported temporary insomnia in the nights immediately after the terrorist attacks on September 11, 2001. 


Chronic insomnia is defined as having symptoms at least 3 nights per week for more than 1 month. Most cases of chronic insomnia are secondary, which means they are due to another disorder or medications. Primary chronic insomnia is a distinct sleep disorder; its cause is not yet well understood. About 30–40 percent of adults say they have some symptoms of insomnia within any given year, and about 10–15 percent of adults say they have chronic insomnia. Chronic insomnia becomes more common with age, and women are more likely than men to report having insomnia.

Insomnia often causes problems during the day, such as extreme sleepiness, fatigue, a lack of energy, difficulty concentrating, depressed mood, and irritability. Thus, untreated insomnia can impair quality of life as much as, or more than, other chronic medical problems.

Chronic insomnia is often caused by one or more of the following:

-      A disease or mood disorder. The most common causes of insomnia are depression and/or anxiety disorders. Neurological disorders, such as Alzheimer’s or Parkinson’s disease, also can have insomnia as a symptom. Chronic insomnia can result from thyroid dysfunction, arthritis, asthma, or other medical conditions in which symptoms become more troublesome at night, making it difficult to fall asleep or stay asleep.
-      Various prescribed and over-the-counter medications that can disrupt sleep, such as decongestants, certain pain relievers, and steroids.
-      Sleep-disrupting behavior such as drinking alcohol, exercising shortly before bedtime, ingesting caffeine late in the day, watching TV or reading while in bed, or irregular sleep schedules due to shift work or other causes.
-      Another sleep disorder, such as sleep apnea or restless legs syndrome.

Some people, however, have primary chronic insomnia. This condition is linked to a tendency to be more “revved up” than normal (hyperarousal). People who have primary chronic insomnia may have heightened levels of certain hormones, higher body temperatures, faster heart rates, and a different pattern of brain waves while they sleep.

Doctors diagnose insomnia based mainly on sleep history, often by reviewing a sleep diary. An overnight sleep recording may be required if another sleep disorder is suspected. Doctors also will try to diagnose and treat any other underlying medical or psychological problems as well as identify behaviors that might be causing the insomnia.

Often, people who have insomnia enter into a vicious cycle—because they’ve had trouble sleeping on previous nights, they become anxious at the slightest sign that they may not be falling asleep right away. That anxiety can make it more difficult for them to fall asleep. The more time they spend in bed not sleeping, and watching the clock, the more their anxiety—and sleeplessness—increases.

To break that cycle of anxiety and negative conditioning, experts recommend going to bed only when you’re sleepy. If you can’t fall asleep (or fall back to sleep) within 20 minutes, get out of bed, go into another room, and do a relaxing activity (such as reading) until you feel sleepy again. Then return to bed. Studies have shown that this reconditioning therapy is an effective way to treat insomnia.

Relaxation therapy is another strategy that works for some people who have insomnia. Relaxation therapy may include meditation and other mental relaxation techniques. It also may include physical relaxation techniques, such as progressively tensing and then relaxing each of the muscle groups in your body before sleep. Another method is to focus on breathing deeply. Relaxation therapy can help your body and mind slow down so that you can fall asleep more easily at bedtime.

Sleep restriction therapy also works for some people who have insomnia. Calculate your average sleep time over the course of a week, and then limit your nightly sleep time to that average. Gradually add more sleep time each night until you achieve a more normal night’s sleep. You should avoid daytime naps longer than 15–20 minutes during sleep restriction therapy. Napping can make it harder to fall asleep at night, which may prolong insomnia. In addition, during sleep restriction therapy, avoid driving a car or operating dangerous machinery until you are getting enough sleep at night.

All of these behavioral changes are part of a treatment called cognitive behavioral therapy. Cognitive behavioral therapy also can be used to replace negative thoughts about sleep, such as “I’ll never fall asleep without sleeping pills,” with more realistic positive thinking. Cognitive behavioral therapy is effective in most people who have chronic insomnia.

Some people who have chronic insomnia that is not corrected by behavioral therapy or treatment of an underlying condition may need a prescription medication. You should talk to a doctor before trying to treat insomnia with alcohol, over-the-counter or prescribed short-acting sedatives, or sedating antihistamines that induce drowsiness.

The benefits of these treatments are limited, and they have risks. Some may help you fall asleep but leave you feeling unrefreshed in the morning. Others have longer lasting effects and leave you feeling still tired and groggy in the morning. Some also may lose their effectiveness over time. Doctors may prescribe sedating antidepressants for insomnia, but the effect iveness of these medicines in people who do not have depression is not known, and there are significant side effects.

To treat their insomnia, some people pursue “natural” remedies, such as melatonin supplements or valerian teas or extracts. These remedies are available over the counter. Little evidence exists that melatonin can help relieve insomnia. Studies with valerian also have been inconclusive, and the actual dose and purity of various supplements, extracts, or teas that contain valerian may vary from product to product. In addition, because melatonin, valerian, and other natural remedies are not regulated by the Food and Drug Administration, their safety is not monitored.

Sleep Apnea

In people who have sleep apnea (also referred to as sleep-disordered breathing), breathing briefly stops or becomes very shallow during sleep. This change is caused by intermittent blocking of the upper airway, usually when the soft tissue in the rear of the throat collapses and partially or completely closes the airway. Each pause in breathing typically lasts 10–120 seconds and may occur 20–30 times or more each sleeping hour. 

If you have sleep apnea, not enough air can flow into your lungs through your mouth and nose during sleep, even though breathing efforts continue. When this happens, the amount of oxygen in your blood decreases. Your brain responds by awakening you enough to tighten the upper airway muscles and open your windpipe. Normal breaths then start again, often with a loud snort or choking sound. Although people who have sleep apnea typically snore loudly and frequently, not everyone who snores has sleep apnea. (See “Is Snoring a Problem?”.)

Because people who have sleep apnea frequently go from deeper sleep to lighter sleep during the night, they rarely spend enough time in deep, restorative stages of sleep. They are therefore often excessively sleepy during the day. Such sleepiness is thought to lead to mood and behavior problems, including depression, and it more than triples the risk of being in a traffic or work-related accident.

The many brief drops in blood-oxygen levels that occur during the night can result in morning headaches and trouble concentrating, thinking clearly, learning, and remembering. Additionally, the intermittent oxygen drops and reduced sleep quality together trigger the release of stress hormones. These hormones raise your blood pressure and heart rate and boost the risk of heart attack, stroke, irregular heartbeats, and congestive heart failure. In addition, untreated sleep apnea can lead to changes in energy metabolism (the way your body changes food and oxygen into energy) that increase the risk for developing obesity and diabetes.

Anyone can have sleep apnea. It is estimated that at least 12–18 million American adults have sleep apnea, making it as common as asthma. More than one-half of the people who have sleep apnea are overweight. Sleep apnea is more com mon in men. More than 1 in 25 middle-aged men and 1 in 50 middle-aged women have sleep apnea along with extreme daytime sleepiness. About 3 percent of children and 10 percent or more of people over age 65 have sleep apnea. This condi tion occurs more frequently in African Americans, Asians, Native Americans, and Hispanics than in Caucasians.

More than one-half of all people who have sleep apnea are not diagnosed. People who have sleep apnea generally are not aware that their breathing stops in the night. They just notice that they don’t feel well rested when they wake up and are sleepy throughout the day. Their bed partners are likely to notice, however, that they snore loudly and frequently and that they often stop breathing briefly while sleeping. Doctors suspect sleep apnea if these symptoms are present, but the diagnosis must be confirmed with overnight sleep monitoring. (See “How Are Sleep Disorders Diagnosed?”.) This monitoring will reveal pauses in breathing, frequent sleep arousals (changes from sleep to wakefulness), and intermittent drops in levels of oxygen in the blood.

Like adults who have sleep apnea, children who have this disorder usually snore loudly, snort or gasp, and have brief pauses in breathing while sleeping. Small children often have enlarged tonsils and adenoids that increase their risk for sleep apnea. But doctors may not suspect sleep apnea in children because, instead of showing the typical signs of sleepiness during the day, these children often become agitated and may be considered hyperactive. The effects of sleep apnea in children may include poor school performance and difficult, aggressive behavior.

A number of factors can make a person susceptible to sleep apnea. These factors include:

-      Throat muscles and tongue that relax more than normal while asleep
-      Enlarged tonsils and adenoids
-      Being overweight—the excess fat tissue around your neck makes it harder to keep the throat area open
-      Head and neck shape that creates a somewhat smaller airway size in the mouth and throat area
-      Congestion, due to allergies, that also can narrow the airway
-      Family history of sleep apnea

If your doctor suspects that you have sleep apnea, you may be referred to a sleep specialist. Some of the ways to help diagnose sleep apnea include:

-      A medical history that includes asking you and your family questions about how you sleep and how you function during the day.
-      Checking your mouth, nose, and throat for extra or large tissues—for example, checking the tonsils, uvula (the tissue that hangs from the middle of the back of the mouth), and soft palate (the roof of your mouth in the back of your throat).
-      An overnight recording of what happens with your breathing during sleep (polysomnogram, or PSG).
-      A multiple sleep latency test (MSLT), usually done in a sleep center, to see how quickly you fall asleep at times when you would normally be awake. (Falling asleep in only a few minutes usually means that you are very sleepy during the day. Being very sleepy during the day can be a sign of sleep apnea.)

Once all the tests are completed, the sleep specialist will review the results and work with you and your family to develop a treatment plan. Changes in daily activities or habits may help reduce your symptoms:

-      Sleep on your side instead of on your back. Sleeping on your side will help reduce the amount of upper airway collapse during sleep.
-      Avoid alcohol, smoking, sleeping pills, herbal supplements, and any other medications that make you sleepy. They make it harder for your airways to stay open while you sleep, and sedatives can make the breathing pauses longer and more severe. Tobacco smoke irritates the airways and can help trigger the intermittent collapse of the upper airway.
-      Lose weight if you are overweight. Even a little weight loss can sometimes improve symptoms.

These changes may be all that are needed to treat mild sleep apnea. However, if you have moderate or severe sleep apnea, you will need additional, more direct treatment approaches.

Continuous positive airway pressure (CPAP) is the most effective treatment for sleep apnea in adults. A CPAP machine uses mild air pressure to keep your airways open while you sleep. The machine delivers air to your airways through a specially designed nasal mask. The mask does not breathe for you; the flow of air creates increased pressure to keep the airways in your nose and mouth more open while you sleep. The air pressure is adjusted so that it is just enough to stop your airways from briefly becoming too small during sleep. The pressure is constant and continuous. Sleep apnea will return if CPAP is stopped or if it is used incorrectly.

People who have severe sleep apnea symptoms generally feel much better once they begin treatment with CPAP. CPAP treatment can cause side effects in some people. Possible side effects include dry or stuffy nose, irritation of the skin on the face, bloating of the stomach, sore eyes, or headaches. If you have trouble with CPAP side effects, work with your sleep specialist and support staff. Together, you can do things to reduce or eliminate these problems.

Currently, no medications cure sleep apnea. However, some prescription medications may help relieve the excessive sleepiness that sometimes persists even with CPAP treatment of sleep apnea.

Another treatment approach that may help some people is the use of a mouthpiece (oral or dental appliance). If you have mild sleep apnea or do not have sleep apnea but snore very loudly, your doctor or dentist also may recommend this. A custom-fitted plastic mouthpiece will be made by a dentist or an orthodontist (a specialist in correcting teeth or jaw problems). The mouthpiece will adjust your lower jaw and tongue to help keep the airway in your throat more open while you are sleeping. Air can then flow more easily into your lungs because there is less resistance to breathing. Following up with the dentist or orthodontist is important to correct any side effects and to be sure that your mouthpiece continues to fit properly. It is also important to have a followup sleep study to see whether your sleep apnea has improved.

Some people who have sleep apnea may benefit from surgery; this depends on the findings of the evaluation by the sleep specialist. Removing tonsils and adenoids that are blocking the airway is done frequently, especially in children. Uvulopalatopharyngoplasty (UPPP) is a surgery for adults that removes the tonsils, uvula, and part of the soft palate. Tracheostomy is a surgery used rarely and only in severe sleep apnea when no other treatments have been successful. A small hole is made in the windpipe, and a tube is inserted. Air will flow through the tube and into the lungs, bypassing the obstruction in the upper airway.
         

How Are Sleep disorders diagnosed?

Depending on your symptoms, your doctor will gather information and consider several possible tests when trying to diagnose a sleep disorder:

Sleep history and sleep log. Your doctor will ask you how many hours you sleep each night, how often you awaken during the night and for how long, how long it takes you to fall asleep, how well rested you feel upon awakening, and how sleepy you feel during the day. Your doctor may ask you to keep a sleep diary for a few weeks. (See “Sample Sleep Diary”.) Your doctor also may ask you whether you have any symptoms of sleep apnea or restless legs syndrome, such as loud snoring, snorting or gasping, morning headaches, tingling or unpleasant sensations in the limbs that are relieved by moving them, and jerking of the limbs during sleep. Your sleeping partner may be asked whether you have some of these symptoms, as you may not be aware of them yourself.

Sleep recording in a sleep laboratory (polysomnogram). A sleep recording or polysomnogram (PSG) is usually done while you stay overnight at a sleep center or sleep laboratory. Electrodes and other monitors are placed on your scalp, face, chest, limbs, and finger. While you sleep, these devices measure your brain activity, eye movements, muscle activity, heart rate and rhythm, blood pressure, and how much air moves in and out of your lungs. This test also checks the amount of oxygen in your blood. A PSG test is painless. In certain circumstances, the PSG can be done at home. A home monitor can be used to record heart rate, how air moves in and out of your lungs, the amount of oxygen in your blood, and your breathing effort.

Multiple sleep latency test (MSLT). This daytime sleep study measures how sleepy you are and is particularly useful for diagnosing narcolepsy. The MSLT is conducted in a sleep laboratory and typically done after an overnight sleep recording (PSG). In this test, monitoring devices for sleep stage are placed on your scalp and face. You are asked to nap four or five times for 20 minutes every 2 hours during the day. Technicians note how quickly you fall asleep and how long it takes you to reach various stages of sleep, especially REM sleep, during your naps. Normal individuals either do not fall asleep during these short designated naptimes or take a long time to fall asleep. People who fall asleep in less than 5 minutes are likely to require treatment for a sleep disorder, as are those who quickly reach REM sleep during their naps.

It is important to have a sleep specialist interpret the results of your PSG or MSLT. See “How To Find a Sleep Center and Sleep Specialist”.


Restless Legs Syndrome

Restless legs syndrome (RLS) causes an unpleasant prickling or tingling in the legs, especially in the calves, that is relieved by moving or massaging them. People who have RLS feel a need to stretch or move their legs to get rid of the uncomfortable or painful feelings. As a result, it may be difficult to fall asleep and stay asleep. One or both legs may be affected. Some people also feel the sensations in their arms. These sensations also can occur when lying down or sitting for long periods of time, such as while at a desk, riding in a car, or watching a movie.

Many people who have RLS also have brief limb movements during sleep, often with abrupt onset, occurring every 5–90 seconds. This condition, known as periodic limb movements in sleep (PLMS), can repeatedly awaken people who have RLS, reducing their total sleep time and interrupting their sleep. Some people have PLMS but have no abnormal sensations in their legs while awake.

RLS affects 5–15 percent of Americans, and its prevalence increases with age. RLS occurs more often in women than men. One study found that RLS accounted for one-third of the insomnia seen in patients older than age 60. Children also can have RLS. In children, the condition may be associated with symptoms of attention-deficit hyperactivity disorder. However, it’s not fully known how the disorders are related. Sometimes “growing pains” can be mistaken for RLS.

RLS is often inherited. Pregnancy, kidney failure, and anemia related to iron or vitamin deficiency can trigger or worsen RLS symptoms. Researchers suspect that these conditions cause an iron deficiency that results in a lack of dopamine, which is used by the brain to control physical sensation and limb movements. Doctors usually can diagnose RLS by patients’ symptoms and a telltale worsening of symptoms at night or while at rest. Some doctors may order a blood test to check ferretin levels (ferretin is a form of iron). Doctors also may ask people who have RLS to spend a night in a sleep laboratory, where they are monitored to rule out other sleep disorders and to document the excessive limb movements.

RLS is treatable but not always curable. Dramatic improvements are seen quickly when patients are given dopamine-like drugs or iron supplements. Alternatively, people who have milder cases may be treated successfully with sedatives or behavioral strategies. These strategies include stretching, taking a hot bath, or massaging the legs before bedtime. Avoiding caffeinated beverages also can help reduce symptoms, and certain medications (e.g., some antidepressants, particularly selective serotonin reuptake inhibitors) may cause RLS. If iron or vitamin deficiency underlies RLS, symptoms may improve with prescribed iron, vitamin B12, or folate supplements. Some people may require anticonvulsant medications to control the creeping and crawling sensations in their limbs. Others who have severe symptoms that are associated with another medical disorder or that do not respond to normal treatments may need to be treated with pain relievers.

Narcolepsy

Narcolepsy’s main symptom is extreme and overwhelming daytime sleepiness, even after adequate nighttime sleep. In addition, nighttime sleep may be fragmented by frequent awakenings. People who have narcolepsy often fall asleep at inappropriate times and places. Although TV sitcoms occasionally feature these individuals to generate a few laughs, narcolepsy is no laughing matter. People who have narcolepsy experience daytime “sleep attacks” that last from seconds to more than one-half hour, can occur without warning, and may cause injury. These embarrassing sleep spells also can make it difficult to work and to maintain normal personal or social relationships.

With narcolepsy, the usually sharp distinctions between being asleep and awake are blurred. Also, people who have narcolepsy tend to fall directly into dream-filled REM sleep, rather than enter REM sleep gradually after passing through the non-REM sleep stages first.

In addition to overwhelming daytime sleepiness, narcolepsy has three other commonly associated symptoms, but these may not occur in all people:

-      Sudden muscle weakness (cataplexy). This weakness is similar to the paralysis that normally occurs during REM sleep, but it lasts a few seconds to minutes while an individual is awake. Cataplexy tends to be triggered by sudden emotional reactions, such as anger, surprise, fear, or laughter. The weakness may show up as limpness at the neck, buckling of the knees, or sagging facial muscles affecting speech, or it may cause a complete body collapse.

-      Sleep paralysis. People who have narcolepsy may experience a temporary inability to talk or move when falling asleep or waking up, as if they were glued to their beds.

-      Vivid dreams. These dreams can occur when people who have narcolepsy first fall asleep or wake up. The dreams are so lifelike that they can be confused with reality.

Experts estimate that as many as 350,000 Americans have narcolepsy, but fewer than 50,000 are diagnosed. The disorder may be as widespread as Parkinson’s disease or multiple sclerosis, and more prevalent than cystic fibrosis, but it is less well known. Narcolepsy is often mistaken for depression, epilepsy, or the side effects of medicines.

Narcolepsy can be difficult to diagnose in people who have only the symptom of excessive daytime sleepiness. It is usually diagnosed during an overnight sleep recording (PSG) that is followed by an MSLT. (See “How Are Sleep Disorders Diagnosed?”.) Both tests reveal symptoms of narcolepsy—the tendency to fall asleep rapidly and enter REM sleep early, even during brief naps.

Narcolepsy can develop at any age, but the symptoms tend to appear first during adolescence or early adulthood. About 1 of every 10 people who have narcolepsy has a close family member who has the disorder, suggesting that one can inherit a tendency to develop narcolepsy. Studies suggest that a substance in the brain called hypocretin plays a key role in narcolepsy. Most people who have narcolepsy lack hypocretin, which promotes wakefulness. Scientists believe that an autoimmune reaction—perhaps triggered by disease, viral illness, or brain injury— specifically destroys the hypocretin-generating cells in the brains of people who have narcolepsy.

Eventually, researchers may develop a treatment for narcolepsy that restores hypocretin to normal levels. In the meantime, most people who have narcolepsy find some to all of their symptoms relieved by various drug treatments. For example, central nervous system stimulants can reduce daytime sleepiness. Antidepressants and other drugs that suppress REM sleep can prevent muscle weakness, sleep paralysis, and vivid dreaming. Doctors also usually recommend that people who have narcolepsy take short naps (10–15 minutes) two or three times a day, if possible, to help control excessive daytime sleepiness.

Parasomnias (Abnormal Arousals)

In some people, the walking, talking, and other body functions normally suppressed during sleep occur during certain sleep stages. Alternatively, the paralysis or vivid images usually experienced during dreaming may persist after awakening. These occurrences are collectively known as parasomnias and include confusional arousals (a mixed state of being both asleep and awake), sleep talking, sleep walking, night terrors, sleep paralysis, and REM sleep behavior disorder (acting out dreams). Most of these disorders— such as confusional arousals, sleep walking, and night terrors—are more common in children, who tend to outgrow them once they become adults. People who are sleep-deprived also may experience some of these disorders, including sleep walking and sleep paralysis. Sleep paralysis also commonly occurs in people who have narcolepsy. Certain medications or neurological disorders appear to lead to other parasomnias, such as REM sleep behavior disorder, and these parasomnias tend to occur more in elderly people. If you or a family member has persistent episodes of sleep paralysis, sleep walking, or acting out of dreams, talk with your doctor. Taking measures to assure the safety of children and other family members who have partial arousals from sleep is very important.