Patient information: Insomnia

INTRODUCTION

Insomnia is defined as difficulty falling asleep, staying asleep, or unrefreshing sleep. In general, people with insomnia sleep less or sleep poorly despite having an adequate chance to sleep. The poor sleep may lead to difficulty functioning during the daytime. Insomnia is not defined by the number of hours slept because "sufficient sleep" can vary from one person to another. Sleep requirements may also decrease with age.

Insomnia is the most common sleep complaint in the United States. While almost everyone has an occasional night of poor sleep, approximately 10 percent of adults have long-term or chronic insomnia.

This topic will review the symptoms, causes, and diagnosis of insomnia. Treatment of insomnia is discussed separately. (See "Patient information: Insomnia treatments".)

INSOMNIA SYMPTOMS

Common symptoms of insomnia include:

• Difficulty falling asleep or staying asleep
• Variable sleep, such as several nights of poor sleep followed by a night of better sleep.
• Daytime fatigue or sleepiness
• Forgetfulness
• Poor concentration
• Irritability
• Anxiety
• Depression
• Reduced motivation or energy
• Increased errors or accidents
• Ongoing worry about sleep

For many people, the symptoms of insomnia interfere with personal relationships and job performance. In one survey, people who experienced chronic insomnia had a two-fold increased risk of automobile accidents compared to people who were fatigued for other reasons [1].

People with insomnia have an impaired sense of sleep. They may feel that they have not slept, even if testing shows that they have. They may also feel more fatigued than individuals without insomnia, even if testing indicates that they are less sleepy. This impaired sense of sleep may be related to a problem with the body's sleep-arousal system, which normally helps a person feel awake after sleeping and to feel tired before going to bed.

One result of poor sleep is that some people are concerned that they will become sleep-deprived and will suffer from serious consequences associated with significant sleep loss. This concern grows as inability to sleep continues so that it becomes increasingly difficult to fall asleep. It is important that patients not be caught in this cycle and understand that they are sleeping more than it seems; sometimes a bed partner report can help with this.

INSOMNIA CAUSES

Insomnia may have many causes:

Short-term insomnia — Short-term insomnia lasts three months or less and is usually caused by physical, psychological, psychosocial, interpersonal, or environmental stressors. It often resolves when the stressor resolves. Possible stressors include the following:

• Changes in the sleeping environment (temperature, light, noise)
• Stress, such as the loss of a loved one, divorce, or job loss
• Recent illness, surgery, or sources of pain
• Use or withdrawal from stimulants (caffeine), certain medications (theophylline, beta blockers, steroids, thyroid replacement, and asthma inhalers), illegal drugs (cocaine and methamphetamine), or alcohol

Traveling across time zones is another common cause of short-term insomnia known as jet lag. Jet lag may occur regardless of the direction of travel, although it is most pronounced when traveling west to east. Most people require several days to adjust their sleep pattern to the new time zone. Other tips are provided here (table 1).

Insomnia is common in individuals who work the night shift (ie, third shift). Affected workers are sleepy at work and while driving home in the morning, but have difficulty maintaining sleep past noon. The sleep problems can be resolved by transferring from the night shift or by adopting a daily sleep routine that is consistent seven days per week for several weeks.

Long-term insomnia — Long-term insomnia lasts longer than one month. Common causes include the following:

• Mental health problems, such as depression, anxiety disorders (including panic attacks), and posttraumatic stress disorder
• Medical illnesses, especially those that cause pain, stress, or difficulty breathing
• Neurological disorders, such as Parkinson disease and Alzheimer disease
• Other sleep disorders, such as sleep apnea, restless legs syndrome, sleep apnea, periodic limb movements, and circadian rhythm disorders (table 2) (see "Patient information: Sleep apnea in adults")

• Medications or illicit drug use
• Primary insomnia — Generally speaking, insomnia is designated as an independent disorder if it is particularly prominent or if there is no identifiable condition, medication, or substance that is causing poor sleep (table 3).

Short duration sleep and sleep deprivation — Insomnia is frequently confused with short sleep requirement and sleep deprivation:

• Sleeping for only a short period of time is common among people who have insomnia, but some normal individuals require little sleep and can function without difficulty after sleeping for a reduced number of hours. People who sleep less but have no residual daytime sleepiness are called short sleepers and are not considered to be having a sleep problem.

In addition, sleep requirements may decrease with age. A decrease in the amount of sleep required by an individual does not necessarily mean that the person has insomnia, unless the decreased sleep is associated with daytime symptoms.

• People with sleep deprivation and insomnia sleep for a short duration and have difficulty functioning during the daytime. However, sleep deprived individuals will rapidly fall asleep if given the opportunity.

Chronic loss of sleep, caused by spending fewer than 8 hours in bed on most nights is probably the most common cause of excessive sleepiness in the general population. Chronic loss of sleep affects approximately one-third of normal adults. However, voluntary loss of sleep is much different from insomnia, which is the inability to sleep given an appropriate opportunity.

INSOMNIA DIAGNOSIS

An insomnia evaluation generally begins by asking the patient to recall sleep times and sleep problems over a typical 24-hour period. The bed partner or caregiver can also provide helpful information because the patient may not be aware of what happens while he/she sleeps.

The person may also be asked to describe sleep times and problems over a typical week to identify abnormalities that do not occur every night. Some patients are also asked to complete a daily sleep log, which requires that they record sleep times and problems for one to two weeks (graph 1).

A person is said to have insomnia if he or she has difficulty sleeping despite having a chance to sleep and has difficulty functioning during the daytime.

Additional information is typically required to determine the cause of the insomnia:

• When did sleep problems begin? How severe is insomnia?
• Are sleep and wake times similar from one day to the next?
• How much time is spent in lying in bed?
• Is the bedroom is used solely for sleep?
• Is the person active or does he/she exercise?
• Is the person exposed to sunlight? At what time?
• Family history of insomnia?
• Any family, work, social, financial stressors?
• Any medical, psychiatric, or neurological conditions?
• Medications (prescription, non-prescription, herbal)?
• Illicit drug use?
• Caffeine and alcohol intake?
• Symptoms and signs of other sleep disorders, such as snoring or breathing abnormally during asleep?

A physical examination may be performed. This helps to determine if there are medical or neurologic conditions that may be causing or worsening the patient's sleep complaints.

A clinician may also use tests and questionnaires to help identify psychological problems, like depression, that could be related to the insomnia symptoms. Laboratory tests may be recommended to help identify underlying medical or sleep disorders, although this is not required for every patient with insomnia. Laboratory tests may include polysomnography or actigraphy:

• Polysomnography — Polysomnography is a formal sleep study done in a sleep laboratory. It uses monitors that are attached to the patient's body to record movement, brain activity, breathing, and other physiologic functions. This test may be used when an underlying sleep disorder is suspected or if the insomnia has not responded to prior treatment.
• Actigraphy — Actigraphy records activity and movement with a monitor or motion detector, generally worn on the wrist. The test is conducted over several days and nights at home to gather information about how much a person is actually sleeping and at what time sleep occurs.

INSOMNIA TREATMENT

The treatment of insomnia is discussed separately. (See "Patient information: Insomnia treatments".)

WHERE TO GET MORE INFORMATION

Your healthcare provider is the best source of information for questions and concerns related to your medical problem. Because no two people are exactly alike and recommendations can vary from one person to another, it is important to seek guidance from a provider who is familiar with your individual situation.

This discussion will be updated as needed every four months on our web site (www.uptodate.com/patients). Additional topics as well as selected discussions written for healthcare professionals are also available for those who would like more detailed information.

Some of the most pertinent include:

Patient Level Information:
Patient information: Insomnia treatments
Patient information: Sleep apnea in adults

Professional Level Information:
Classification of sleep disorders
Diagnostic evaluation of insomnia
Overview of insomnia
Physiology and clinical use of melatonin
Treatment of insomnia

A number of web sites have information about medical problems and treatments, although it can be difficult to know which sites are reputable. Information provided by the National Institutes of Health, national medical societies and some other well-established organizations are often reliable sources of information, although the frequency with which they are updated is variable.

• National Library of Medicine

      (www.nlm.nih.gov/medlineplus/healthtopics.html)

• American Academy of Sleep Medicine

      (www.aasmnet.org)

• National Center on Sleep Disorders Research

      (www.nhlbi.nih.gov/about/ncsdr)

• National Heart, Lung, and Blood Institute

      (www.nhlbi.nih.gov/health/public/sleep/index.htm)

• National Sleep Foundation

      (www.sleepfoundation.org)

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