(See also Overview of Sleep Overview of Sleep Sleep is necessary for survival and good health, but why sleep is needed and exactly how it benefits people are not fully understood. One of sleep's benefits is its restorative effect on people's... read more .)
Various unconscious and largely unremembered behaviors can occur during sleep in children and adults.
Just before falling asleep, almost all people occasionally experience brief, involuntary jerks of the arms or the entire body. Occasionally, the legs jerk. Some people also experience sleep paralysis (attempting but being unable to move) or brief fleeting images or thoughts when they are just falling asleep or awakening. People may clench or grind their teeth or have nightmares.
Sleepwalking, head-banging, and night terrors are more common among children and can be very distressing for their parents. Usually, children do not remember these episodes. Other parasomnias include nightmares, rapid eye movement (REM) sleep behavior disorder, and sleep-related leg cramps.
These frightening episodes result in sitting up, screaming, and flailing about. The eyes are wide open, and the heart races. People appear very frightened. Episodes usually occur when people are partially aroused or when they just awakened from the deepest stage of nonrapid eye movement (NREM) sleep, typically during the first few hours of the night.
Night terrors differ from nightmares and may lead to sleepwalking.
Night terrors are more common among children. Children should not be awakened because doing so makes them even more frightened. Although children appear highly distressed, they have no memory for the events or mental images after awakening and do not have psychologic problems as a result of these behaviors. Parents need not be overly distressed. Children usually stop having episodes when they become older.
Episodes in adults are often associated with psychologic problems or alcohol use disorder.
For children, reassurance from their parents may be all that is needed. If school work or other activities are affected, treating older children with certain benzodiazepines Antianxiety and Sedative Drugs Antianxiety and sedative drugs are prescription drugs used to relieve anxiety and/or help with sleep, but their use can result in dependency and a substance use disorder. Using prescription... read more (such as diazepam, clonazepam, or alprazolam) may help. These drugs, which are used to treat anxiety (antianxiety drugs Treatment ) and induce sleep (sedatives), are given 90 minutes before bedtime. They can help children sleep and make night terrors less likely to occur. However, long-term use of benzodiazepines can lead to drug dependence Antianxiety and Sedative Drugs Antianxiety and sedative drugs are prescription drugs used to relieve anxiety and/or help with sleep, but their use can result in dependency and a substance use disorder. Using prescription... read more . Thus, these drugs are usually taken for only a relatively short time (about 3 to 6 weeks).
Adults may benefit from psychotherapy or drug treatment.
Nightmares are vivid, frightening dreams, followed by sudden awakening. Children are more likely to have nightmares than adults. Nightmares occur during rapid eye movement (REM) sleep.
Nightmares are more likely to occur when people are under stress, have a fever, are excessively tired, or have consumed alcohol.
Treatment of nightmares, if necessary, focuses on any underlying problem.
Sleepwalking, most common in late childhood and adolescence, is walking in a semiconscious manner without being consciously aware of it. It occurs during the deepest stage of NREM sleep.
Sleepwalkers may mumble repetitiously and can hurt themselves by walking into obstacles. Most sleepwalkers have no memory of sleepwalking.
Not getting enough sleep and behaving in ways that are not conducive to sleep (see table Changes in Behavior to Improve Sleep Changes in Behavior to Improve Sleep ) can make sleepwalking more likely. For example, consuming caffeine, exercising, or watching an exciting television show before bedtime may trigger sleepwalking.
Usually, no specific treatment is necessary unless sleepwalking results in injury.
The following general measures may help make sleepwalking less likely:
Taking measures to improve sleep—for example, near bedtime, avoiding doing anything stimulating (such as exercising or consuming caffeine)
Installing alarms to awaken the sleepwalker when the sleepwalker leaves the bed
Installing door alarms
The following measures may help prevent injuries during sleepwalking:
Gently leading the sleepwalker back to bed, rather than forcibly awakening the sleepwalker, which may agitate the sleepwalker
Removing obstacles or breakable objects that may be in the sleepwalker's path
Keeping windows closed and locked
For the sleepwalker, sleeping in a low bed or on a mattress on the floor to prevent falls from bed when the sleepwalker attempts to get out of bed
Benzodiazepines Antianxiety and Sedative Drugs Antianxiety and sedative drugs are prescription drugs used to relieve anxiety and/or help with sleep, but their use can result in dependency and a substance use disorder. Using prescription... read more , particularly clonazepam, usually help if general measures are ineffective. However, these drugs have significant side effects, such as drowsiness during the day. Long-term use of benzodiazepines can lead to drug dependence Antianxiety and Sedative Drugs Antianxiety and sedative drugs are prescription drugs used to relieve anxiety and/or help with sleep, but their use can result in dependency and a substance use disorder. Using prescription... read more .
Rapid eye movement sleep behavior disorder
This disorder involves speaking (often profanely) and sometimes making aggressive movements during rapid eye movement (REM) sleep, usually in response to a dream.
REM sleep behavior disorder is more common among older people. Most people with this disorder have a disorder that causes brain tissue to degenerate, such as Parkinson disease Parkinson Disease (PD) Parkinson disease is a slowly progressive degenerative disorder of specific areas of the brain. It is characterized by tremor when muscles are at rest (resting tremor), increased muscle tone... read more , multiple system atrophy Multiple System Atrophy (MSA) Multiple system atrophy is a progressive, fatal disorder that makes muscles stiff (rigid) and causes problems with movement, loss of coordination, and malfunction of internal body processes... read more , or dementia with Lewy bodies Dementia With Lewy Bodies and Parkinson Disease Dementia Dementia with Lewy bodies is progressive loss of mental function characterized by the development of Lewy bodies in nerve cells. Parkinson disease dementia is loss of mental function characterized... read more , The risk of developing Alzheimer disease Alzheimer Disease Alzheimer disease is a progressive loss of mental function, characterized by degeneration of brain tissue, including loss of nerve cells, the accumulation of an abnormal protein called beta-amyloid... read more may be somewhat increased. Some people develop Parkinson disease years after REM sleep behavior disorder is diagnosed.
People with REM sleep behavior disorder, unlike those with night terrors, are sometimes aware of having dreamed vividly during these episodes when they wake up the next day.
Aggressive movements may include waving the arms, punching, and kicking. The aggressive behavior is not intentional and is not directed at anyone. People may inadvertently injure themselves or their bed partner. Also, this behavior interferes with sleep, making people tired and sleepy during the day.
Doctors can often diagnose REM sleep behavior disorder based on symptoms reported by the person or the person’s bed partner. But if they cannot, polysomnography Testing with electromyography Electromyography and Nerve Conduction Studies Diagnostic procedures may be needed to confirm a diagnosis suggested by the medical history and neurologic examination. Electroencephalography (EEG) is a simple, painless procedure in which... read more (EMG) is usually done.
To check for disorders that cause degeneration of the brain, doctors do a neurologic examination Neurologic Examination When a neurologic disorder is suspected, doctors usually evaluate all of the body systems during the physical examination, but they focus on the nervous system. Examination of the nervous system—the... read more to evaluate mental status and brain and nerve function. If an abnormality is detected, computed tomography (CT) or magnetic resonance imaging (MRI) may be done.
There is no cure for the disorder. But clonazepam, a benzodiazepine (which is a sedative), relieves symptoms in most people. A low dose is effective. The drug is usually continued indefinitely. Melatonin may also help relieve symptoms of REM sleep behavior disorder.
Bed partners should be warned about the possibility of harm and may wish to sleep in another bed until the drug begins to work. People with REM sleep behavior disorder should remove sharp objects and furniture from next to their bed.
Sleep-related leg cramps
Muscle cramps Muscle Cramps A cramp is a sudden, brief, unintended (involuntary), and usually painful contraction of a muscle or group of muscles. Muscle cramps can be a symptom of nervous system malfunction. The most... read more often occur in the calf or foot during sleep in otherwise healthy middle-aged and older people.
Doctors usually diagnose sleep-related leg cramps based on symptoms after they rule out other physical problems or disabilities. No further testing is needed.
To prevent these cramps, people should stretch the affected muscles for several minutes before going to sleep. Usually, stretching as soon as cramps occur relieves symptoms promptly and is preferred to drug treatment. Avoiding caffeine and other stimulants may help.
Many drugs (such as quinine, calcium and magnesium supplements, diphenhydramine, benzodiazepines, and mexiletine) have been used, but none is likely to be effective. Also, side effects, especially with quinine and mexiletine, may be bothersome.