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Editor: Brigham Narins
Date: 2019
Publisher: Gale, a Cengage Company
Document Type: Disease/Disorder overview
Length: 3,097 words

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Insomnia is the inability to obtain an adequate amount or quality of sleep. The difficulty may be in falling asleep, remaining asleep, or waking up too early, or a combination of all three. Sleeplessness is a symptom that may be caused by physical or mental conditions or circumstances, including a general medical condition or psychiatric disorder.


The U.S. Centers for Disease Control and Prevention estimates that between 50 and 70 million Americans are affected by some type of sleep disorder, and nearly half of the U.S. population reports at least occasional sleeping problems. Accurate data are difficult to gather, as many people misperceive how much sleep they actually get and how many times they normally wake up during the night. It is generally thought, however, that women are more likely than men to suffer from insomnia. As people age, they are also more likely to experience insomnia, as are people who are generally nervous or tense. According to the National Sleep Foundation (NSF), people who are divorced, widowed, or separated are more likely to experience insomnia than married couples, and insomnia is more frequently reported by persons of lower socioeconomic status.

Anti-insomnia drugs Anti-insomnia drugs (Table by PreMediaGlobal. Reproduced by permission of Gale, a part of Cengage Learning.) (Table by PreMediaGlobal. Reproduced by permission of Gale, a part of Cengage Learning.)

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Insomnia is classified both by its nightly symptoms and its duration. Sleep-onset insomnia refers to difficulty falling asleep; maintenance insomnia refers to waking frequently during the night or waking early. Insomnia is also classified in relation to the number of sleepless nights. Short-term insomnia, also called transient or acute insomnia, is a common occurrence and usually lasts only a few days. Long-term or chronic insomnia lasts more than three to four weeks. Insomnia can also be classified as either primary or secondary. Primary insomnia is a disorder that cannot be attributed to another condition or disorder, whereas secondary insomnia can be traced back to a source. Possible sources of secondary insomnia include a medical condition; the use of medications, alcohol, or other substances; or a mental disorder like severe depression.

Sleep is essential for mental and physical restoration. Chronic insomnia increases the risk of personal injury and error because of the fatigue and delayed reflexes experienced due to lack of sleep. Chronic insomnia can also lead to mood disorders like depression. On average, adults require approximately 7–8 hours of sleep each night; teenagers need about 9 hours per night; and infants need 16 to 18 hours of sleep each day to function properly and maintain health.

Not all disruptions in the normal pattern of sleeping and waking are considered insomnia. Such factors as jet lag, unusually high levels of stress, changing work shifts, or other drastic changes in the person's routine can all lead to sleep problems. Unless the problems are ongoing and severe enough that they are causing distress for the person in important areas of life, he or she is not considered to have insomnia.

Stages of sleep

Sleep consists of two separate states that constantly cycle: rapid eye movement (REM), the stage in which most dreaming occurs, and non-REM (NREM). Four stages of sleep take place during NREM: stage I, when the person passes from relaxed wakefulness; stage II, an early stage of light sleep; and stages III and IV, which are increasing degrees of deep sleep. Most stage IV sleep (also called delta sleep) occurs in the first several hours of sleep. A period of REM sleep normally follows a period of NREM sleep.

Causes and symptoms


Sleeplessness or insomnia can have many causes, including physical conditions (such as sleep apnea), mental conditions (such as depression), shift work schedules with irregular hours, or experiencing a traumatic event. In the days immediately following the terrorist attacks on September 11, 2001, 47% of Americans rated their sleep as “poor” or “fair,” according to NSF's “2002 Sleep in America” poll. In comparison, 27% of poll participants rated sleep as poor or fair for most nights of that year.

Transient insomnia is often caused by a temporary situation in a person's life like an argument with a loved one, a brief medical illness, or jet lag. When the situation is resolved or the precipitating factor disappears, the condition goes away, usually without medical treatment. Side effects of such prescription drugs as asthma medicines, steroids, and antidepressants may include insomnia, and it may also be a side effect of such overthe-counter products as nasal decongestants or appetite suppressants.

Chronic insomnia usually has different causes, and there may be more than one factor contributing to sleeplessness. Causes of insomnia include:

  • a medical condition or its treatment, including sleep apnea, diabetes, arthritis, a heart condition, and asthma
  • use of such substances as caffeine, alcohol, and nicotine
  • such psychiatric conditions as mood or anxiety disorders
  • stress or depression, including sadness caused by the loss of a loved one, a relationship, or a job
  • a change in work scheduling
  • a work schedule with nontraditional hours, such as those worked by medical professionals, truck drivers, the military, and persons employed by 24-hour businesses
  • sleep-disordered breathing, including snoring
  • periodic jerky leg movements (nocturnal myoclonus) that occur just as the individual is falling asleep
  • restless legs syndrome, which involves the urge to move the legs and may also include feelings of tingling or cramping
  • repeated nightmares or panic attacks during sleep

Excessive worrying about whether one will be able to fall asleep may also cause insomnia. The concern creates so much anxiety that the individual's bedtime rituals and behavior actually trigger insomnia, a condition called psychophysiological insomnia.


People with insomnia are unable to achieve a good night's sleep and wake up feeling tired. They may have difficulty falling asleep or may be able to fall asleep without a problem but wake up in the early hours of the Page 855  |  Top of Articlemorning. The person is then either unable to go back to sleep or drifts into a restless, unsatisfying sleep. Insomnia is a common condition in the elderly and persons suffering from depression. Sometimes sleep patterns are reversed and the individual has difficulty staying awake during the day and takes frequent naps, with the sleep at night being fitful and frequently interrupted.

The lack of restful sleep may result in daytime symptoms of sleep deprivation, including a lack of concentration, headaches, anxiety, irritability, fatigue, delayed reflexes, and gastrointestinal symptoms. Lack of sleep has also been associated with an increase in appetite, which can lead to weight gain.


Insomnia is a disorder that is usually self-reported; that is, patients usually bring up the subject of sleep problems with their doctors rather than the doctor suggesting the diagnosis. There are no laboratory tests for insomnia, but the doctor may review a patient's health history or order tests to determine whether a medical condition is causing the insomnia. The physician may ask whether the patient is depressed, in pain, under stress, working irregular schedules, or taking any medications. The physician may also suggest keeping a sleep diary, in which the patient notes details such as the time they went to bed, the time(s) at which they got up during the night, their activities before bed, use of caffeine, etc. If the patient has a bed partner, information can be obtained about whether the patient snores or is restless during sleep. This information, together with a medical history and physical examination, can help confirm the doctor's assessment and uncover specific factors related to the insomnia.

Insomnia is included in the Diagnostic and Statistical Manual of Mental Disorders, fifth edition. This edition refers to the condition as insomnia disorder. In order to meet the DSM-5 criteria for insomnia disorder, a person must experience the symptoms for at least a month, and the symptoms must cause them distress or reduce their ability to function successfully. The patient must experience difficulty sleeping for at least three nights per week for a period of at least three months. The symptoms cannot be caused by a different sleep disorder or medical condition or be a side effect of medications or substance abuse, though insomnia may be comorbid with (occur together with) other psychiatric disorders, including mania, depression, and anxiety disorders.


Treatments for insomnia disorder include treating any physical or mental conditions contributing to the sleeplessness as well as exploring changes in lifestyle that may improve the situation (such as changing work schedules). Behavioral and educational therapies, like cognitive-behavioral therapy are usually tried first because they do not have side effects and cannot create a chemical dependence the way some sleep medications can. In seeking treatment, patients may wish to consult a sleep clinic or a doctor who specializes in the treatment of sleep disorders as well as their family doctor. Treatment using a combination of approaches is usually most effective.


Behavioral and lifestyle changes may help patients overcome sleeplessness. Patients should try to go to bed only when sleepy and use the bedroom only for sleep; activities like reading, watching television, or snacking should take place elsewhere. Maintaining a comfortable bedroom temperature, reducing noise, and eliminating light may also help. If a person is unable to fall asleep, he or she can go into another room and do some quiet activity such as reading and return to bed when sleepy. Setting an alarm and getting up every morning at the same time no matter how long a person has slept, may help to establish a regular sleep-wake pattern. Naps during the day should be avoided, but if absolutely necessary, a 30-minute nap early in the afternoon may not interfere with sleep at night.

Sleep-restriction therapy is a technique that restricts the time in bed to the actual time spent sleeping. This approach allows a slight sleep debt to build up, increasing the individual's ability to fall asleep and stay asleep. If a patient sleeps five hours a night, the time in bed is limited to 5–5.5 hours. The time in bed is gradually increased in small segments, with the individual rising at the same time each morning; at least 85% of the time in bed must be spent sleeping.


A physician may determine that drug therapy is necessary to treat insomnia. Drugs may be prescribed if the patient is undergoing a crisis or if insomnia persists after a patient has made lifestyle changes. However, drug therapy is regarded as a short-term remedy, not a longterm solution.

Conventional medications given for insomnia include sedatives, tranquilizers, and antianxiety drugs. All require a doctor's prescription and may be habit-forming. Medications may lose effectiveness over time and can reduce alertness during the day. The medications should be taken up to four times daily or as directed for approximately three to four weeks. The dose will vary Page 856  |  Top of Articlewith the physician, patient, and medication. If insomnia is related to depression, then an antidepressant medication may be helpful.

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Mood disorder—
A group of mental disorders involving a disturbance of mood, along with either a full or partial excessively happy (manic) or extremely sad (depressive) syndrome not caused by any other physical or mental.
Sleep apnea—
A condition in which a person stops breathing while asleep. These periods can last up to a minute or more and can occur many times each hour. In order to start breathing again, the person must become semi-awake. The episodes are not remembered, but the following day the person feels tired and sleepy. Severe sleep apnea can cause other medical problems.
Sleep disorder—
Any condition that interferes with sleep.

Drugs prescribed for improving sleep are called hypnotics. Hypnotics include benzodiazepines, which are prescribed for anxiety and insomnia. Benzodiazepines commonly prescribed for insomnia disorder include triazolam (Halcion), temazepam (Restoril), lorazepam (Ativan), alprazolam (Xanax), flurazepam (Dalmane), and oxazepam (Serax). Other drugs that may be prescribed include zolpidem (Ambien), ramelteon (Rozerem), and eszopiclone (Lunesta). In clinical studies, ramelteon has shown no evidence of potential for abuse, dependence, or withdrawal. Both ramelteon and eszopiclone are approved for long-term use by prescription only.

Over-the-counter sleep products include Nytol, Sominex, Unisom, and Tylenol PM. While these products are usually not addictive, some experts believe they are not very effective in sustaining stage IV sleep and can affect the quality of sleep, resulting in daytime drowsiness.


Alternative treatments may be used in treating both the symptom of insomnia and its underlying causes. Much treatment is centered on herbal remedies, but as the U.S. Food and Drug Administration does not regulate the safety or efficacy of these treatments, consumers should be cautious when using herbal supplements. Persons interested in herbal supplements should consult with their health-care provider or complementary medicine practitioner before taking any herbal remedies. This precaution is especially important because some remedies like melatonin interact with other herbals like valerian and prescription medicines.

VALERIAN. Valerian is one of the herbs most commonly used to treat insomnia. In clinical trials, people who took valerian fell asleep more quickly and experienced improved slumber. Because of the herb's sedative properties, valerian is used to treat both insomnia and anxiety. Valerian is sold commercially in the form of capsules, extracts, and teas. The capsule or extract dosage ranges from 300 to 600 mg; teas may consist of a mixture of herbs with sedative properties, such as valerian, chamomile, hops, lemon balm, passionflower, or St. John's wort. As a sleep aid, valerian should be taken shortly before bedtime. People who have trouble falling asleep may see results quickly. It could take from two weeks to a month before a person with chronic insomnia experiences improved sleep.

MELATONIN. Melatonin is a natural hormone that is secreted from the brain's pineal gland. The gland regulates a person's biological clock, particularly day and night cycles. Supplement melatonin is available to help promote sleep and regulate sleep cycles. Melatonin is generally used as a jet lag remedy and may also help establish sleep patterns for shift workers. It has also been successful in clinical trials in treating sleep problems in children with autism and intellectual disability disorders and in persons who are blind. While melatonin may help people fall asleep more quickly, studies indicate limited success when used for treating insomnia disorder. Melatonin is available in pill form; long-term effects of taking it are not known as of 2018.

MIND AND BODY RELAXATION. Incorporating relaxation techniques into bedtime rituals may help a person go to sleep faster and improve the quality of sleep. Relaxation techniques are safe and may be effective in reducing sleeplessness. Suggestions include learning to substitute pleasant thoughts for unpleasant ones (imagery training) to help reduce worrying, or listening to recordings that combine the sounds of nature with soft relaxing music. Meditation, prayer, and breathing exercises may also be effective.

AROMATHERAPY AND HYDROTHERAPY. Aromatherapy promotes relaxation through the use of essential oils, the aromatic extracts of plants. Essential oils may be used for a soothing bath; applied to the face, neck, shoulders, and pillow; or diffused in air. Dream pillows, also known as sleep pillows, are pillows with an opening to insert essential oils, so that scents such as chamomile or lavender can be smelled while the person attempts to sleep. Hydrotherapy incorporated with aromatherapy consists of a warm bath scented with essential oils, most often rose, Page 857  |  Top of Articlelavender, or marjoram. Valerian may also be added to bath water. Taking a warm bath before bed is thought to naturally reduce the body's temperature, which prepares the body for sleep.

LIGHT THERAPY. Light therapy may help some patients with insomnia, particularly those affected by repeatedly waking in the morning rather than having difficulty falling asleep at night. During a light therapy session, the patient sits in front of a light box for a specified period of time. The rays of the light box mimic those of the sun, helping to reset the patient's biological clock. Light therapy is traditionally used in treating seasonal affective disorder, a depressive condition caused by the relative lack of sunlight during winter months.

MASSAGE THERAPY. Massage therapy promotes relaxation by soothing tense muscles throughout the body. It is especially helpful for restless leg syndrome. A massage once a week by a registered massage therapist may help the individual relieve any stress that is causing sleeplessness.

NUTRITION AND DIETARY THERAPIES. Persons with insomnia should avoid alcohol and caffeine products, which may disrupt the sleep-wake cycle. Eating a healthy diet rich in calcium, magnesium, and the B vitamins, or taking nutritional supplements, may also be beneficial in treating insomnia.


Insomnia disorder can be successfully treated in most adults, although any underlying illness will require treatment in order to correct the related insomnia. Sleep apnea, one possible medical cause of insomnia, is a potentially serious disorder related to breathing difficulties and chronic lung conditions that can be fatal if not treated.

Untreated insomnia has potentially serious consequences, including an increased risk of motor vehicle accidents, impaired school or job performance, and a high rate of absenteeism from work. Though insomnia can be treated, patients who have had insomnia once are at an increased risk for recurrent insomnia.


Prevention of insomnia centers around the promotion of a healthy lifestyle. A balance of rest, recreation, and exercise in combination with stress management, regular physical examinations, and a healthy diet can do much to reduce the risk. Walking is also recommended. However, exercise should be done at least three hours before bedtime, to avoid a stimulating effect. Exercise, relaxation, and nutrition should be considered ongoing preventive measures.

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  • Why can't I sleep through the night?
  • What can I do to help fall asleep and prevent waking up during the night?
  • Is it okay for me to take over-the-counter sleeping pills?
  • Will I be able to enjoy restful sleep again?



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Johnston, Smith L., III. “Societal and Workplace Consequences of Insomnia, Sleepiness, and Fatigue.” Medscape Education (September 29, 2005). (accessed November 2, 2011).

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American Academy of Sleep Medicine, 2510 N Frontage Rd., Darien, IL 60561, (630) 737-9700, Fax: (630) 737-9790,, .

American Sleep Association, 614 South 8th St., Ste. 282, Philadelphia, PA 19147, (443) 593-2285,, .

National Sleep Foundation, 1010 N. Glebe Rd., Suite 310, Arlington, VA 22201, (703) 243-1697, .

Full Text: 

L. Lee Culvert
Revised by Laura Jean Cataldo, RN, EdD
Revised by Heidi Splete

Disclaimer:   This information is not a tool for self-diagnosis or a substitute for professional care.

Source Citation

Source Citation   

Gale Document Number: GALE|CX2491200256