Insomnia is the inability to sleep for a reasonable amount of time to maintain adequate restfulness. It is the most common type of sleep disorder.

Insomnia is not defined by the total number of hours slept. Most adults require seven to eight hours of sleep a night, but some need only four or five.

About one in three American adults experience insomnia in a given year, according to the National Institutes of Health. About one in 10 American adults experience insomnia that is chronic or severe. Insomnia is more common among women (especially after menopause) and the elderly. About half of people over age 65 have frequent sleep problems.

Many conditions can cause insomnia, such as:

• Lifestyle factors (e.g., drinking caffeine or alcohol before bedtime)
• Psychiatric conditions (e.g., depression)
• Other medical conditions (e.g., peptic ulcers)
• Medications
• Other sleep disorders (e.g., sleep apnea)

Symptoms of insomnia may include difficulty falling asleep, waking up frequently during the night, daytime drowsiness or irritability.

Many people visit their physician with complaints of insomnia. A review of their medical history, a physical examination and details of medications and lifestyle may help pinpoint the cause. Patients should also be evaluated for psychiatric conditions. They may be asked to keep a sleep diary to document sleep patterns and behaviors. In some cases, patients may be referred to a sleep center where sleep is analyzed by sleep disorder professionals. This is usually done to rule out other sleep disorders.

Several approaches may be used to treat insomnia, depending on its cause. Lifestyle changes, such as increased exercise or elimination of alcohol or caffeine, may help the condition. Sedative medications may also be prescribed, although they are not a long-term solution. Some forms of therapy, such as relaxation therapy, may help some patients.

Insomnia is difficulty falling asleep or staying asleep, resulting in inadequate length of sleep and/or poor quality of sleep. The disturbances caused by insomnia affect people during their waking hours.

People with insomnia may wake frequently during the night and have difficulty falling back asleep or may wake up too early in the morning. Insomnia is the most common type of sleep disorder.

Sleep requirements differ among individuals. Therefore, insomnia is not defined by how long it takes to fall asleep or the total number of hours spent sleeping. Most adults require seven to eight hours of sleep, but some people need only four to five hours.

Primary insomnia is difficulty with sleep that is diagnosed after other underlying causes (such as medications or diseases) have been either ruled out or treated. Factors such as chronic stress, hyperarousal, poor sleep habits (such as drinking caffeine before sleeping) and behavioral conditioning may contribute to primary insomnia. If insomnia can clearly be attributed to an underlying cause, it is called secondary insomnia. However, when another medical or mental health disorder is also present, it can be difficult to determine whether the insomnia is due to the disorder or if the other disorder is secondary to insomnia. In addition, some people report having insomnia that then cannot be found by a sleep study.

Insomnia may be:

• Transient. Lasting for a few weeks. Most people experience transient insomnia at some point in their lives. It is a common response to jet lag or stressful situations, such as job loss or death of a loved one.
  
  
• Intermittent. Episodes of transient insomnia that occur from time to time.
  
  
• Chronic. Insomnia occurs on most nights or lasts a month or longer. This is often the result of a medical, neurological or psychiatric disorder or other factors.

Research has shown that insomnia can be linked to problems with immune system functioning, muscle endurance and hormones. Insufficient sleep may raise the risk of obesity and type 2 diabetes, according to several recent studies. And it increases the risk of accidents such as car wrecks.

About one in three American adults experience insomnia in a given year, according to the National Institutes of Health. About one in 10 experience insomnia that is chronic or severe. Insomnia is more common among women (especially after menopause) and the elderly. About half of people over age 65 have frequent sleep problems.

Children also experience insomnia, for many of the same reasons as adults, such as stress or poor sleep habits. They can also experience insomnia as a result of nightmares and night terrors.

Changes that occur with age and may affect sleep include:

• Sleep pattern changes. Sleep becomes less restful after age 50. More time is spent in the earlier, transitional stages of sleep than the later stages (deep sleep). The later stages are the most restful kind of sleep.
  
  
• Activity changes. Older adults are less active than younger adults and activity helps facilitate a good night's sleep. Older adults may also have more free time than younger adults and may have habits that interfere with sleep, such as daytime napping and caffeine consumption.
  
  
• Health changes. Chronic pain conditions that may interfere with sleep, such as arthritis or back problems, occur more frequently with age. Also, sleep disorders that result in insomnia, such as sleep apnea (when breathing stops periodically throughout the night) and restless legs syndrome (unpleasant sensations in the legs during the night), increase with age.

There are many causes of insomnia. Lifestyle factors that can cause insomnia include:

• Foods. Foods that contain caffeine, such as chocolate, may cause insomnia. Salty foods may disrupt sleep by causing thirst. Eating too much or too soon before bedtime may also interrupt sleep.
  
  
• Drinks. Drinks that contain caffeine, such as coffee and soft drinks, may result in insomnia. Alcohol may initially induce sleep, but can result in waking up too early.
  
  
• Stress. Life circumstances, such as a new baby, job loss or death of a loved one, are common causes of transient insomnia.
  
  
• Changes in environment or work schedules. Travel between time zones or working the night shift can disrupt the body's circadian rhythm (internal clock that guides the wake-sleep cycle, metabolism, body temperature and other bodily functions). A bed partner's snoring can also cause insomnia.
  
  
• Poor sleep habits. Excessive daytime napping and using the bed for activities other than sleeping and sex can sometimes cause insomnia.

Many medications may also cause insomnia in some people. These may include some medications that are prescribed to treat the condition, especially if they are used for lengthy periods of time.

Numerous medical and mental health conditions may also cause insomnia. Chronic pain diseases such as osteoarthritis and inflammatory conditions such as allergic rhinitis (hay fever) may make it difficult to sleep. People suffering from peptic ulcers often experience insomnia. Hormonal changes in the body also can affect a person’s sleep pattern. Pregnant women require more sleep, especially early in pregnancy, but may also have insomnia as a result of the hormonal changes experienced during pregnancy. After puberty, some teenage girls may experience insomnia as a result of the hormonal changes associated with the onset of menstruation. After menopause, women are at higher risk of chronic insomnia, especially those who experience severe hot flashes. People with mental illnesses such as depression or anxiety disorders are also affected with insomnia.

In addition, other sleep disorders may produce changes in sleep and cause insomnia. These include:

• Sleep apnea. A disorder in which a person's breathing stops and starts many times during sleep.
  
  
• Restless legs syndrome. Sleep disorder characterized by unpleasant sensations in the legs that are described as creeping, crawling, tingling, pulling or painful.
  
  
• Periodic limb movement disorder (nocturnal myoclonus). Characterized by periodic episodes of repetitive jerking and kicking during sleep.
  
  
• Circadian rhythm sleep disorder. Involves disruption of the sleep cycle. Common examples are jet lag and sleep problems associated with shift work.

For many people, a combination of these factors causes insomnia. For example, a person experiencing stress at work may eat or drink later in the evening, resulting in insomnia.

In some cases, the cause of insomnia cannot be determined. This is called idiopathic insomnia. People with idiopathic insomnia often have trouble falling or staying asleep their entire lives. Physicians believe it may be caused by imbalances of certain chemicals in the brain. Patients with idiopathic insomnia often have family members with the condition.

Common signs and symptoms of insomnia may include:

• Difficulty falling asleep
• Difficulty staying asleep or waking up too early
• Waking up feeling tired, even after a full night’s sleep
• Daytime fatigue or sleepiness
• Inability to concentrate
• Irritability
• Anxiety
• Depression
• Forgetfulness
• Chronic pain

Although insomnia may cause tiredness, lack of energy, difficulty concentrating or irritability during daytime hours, some people with the condition experience less sleepiness during the day than people without the condition. This is because some people with insomnia experience problems with the body’s sleep-arousal system, which helps people feel awake after sleeping and tired before going to bed.

People with insomnia may also experience an impaired sense of sleep, meaning they believe they are not sleeping but sleep tests prove they are.

Insomnia may also cause problems with interpersonal relationships and job performance. People who experience sleep deprivation due to chronic insomnia face twice the risk of automobile accidents than those experiencing fatigue for other reasons.

Insomnia may take time to diagnose, depending on its cause. A physical examination and a review of the patient's medical history and medications may be sufficient to pinpoint the source of the problem for most people. If not, physicians may seek to determine whether a medical or psychiatric condition is contributing to insomnia.

Physicians may conduct a sleep history, in which patients are asked questions about sleep habits. Physicians may also ask family members or bed partners to describe symptoms observed while the patient is sleeping. Questions physicians ask patients may include:

• When did your insomnia begin?
  
  
• Is your sleep environment conducive to sleep?
  
  
• Do you experience creeping, crawling or uncomfortable feelings in your legs during the night?
  
  
• Do you snore loudly, gasp, choke or stop breathing during sleep?
  
  
• What are your bedtimes and rise times during the week and on weekends?

Patients may be asked to keep a sleep diary, usually over a two-week period. Information recorded in the diary may include bedtimes, time required to fall asleep, time asleep and feelings of restfulness after awakening. Patients may also be asked to fill out a sleep questionnaire, such as the Epworth Sleepiness Scale. This tool includes questions to measure the likelihood of dozing in certain circumstances, such as sitting and reading.

Patients may be referred to a sleep center where sleep patterns are analyzed in depth by health professionals who specialize in sleep disorders. These tests are usually performed to rule out other conditions, such as sleep apnea. Some common tests that are performed to diagnose sleep disorders include:

• Polysomnogram (sleep study). Painless test conducted overnight while patients are sleeping. Electrodes are placed on the face and scalp before sleep. The test monitors electrical activity of the brain (electroencephalogram), electrical activity of the heart (electrocardiogram), movements of the muscles (electromyogram) and eye movements (electro-oculogram). These are measured as patients move through the different stages of sleep.
  
  
• Multiple sleep latency test (MSLT). Conducted in a similar method as a polysomnogram, but performed during daytime hours. The test is conducted while patients nap during daytime hours.
  
  
• Actigraphy. Records activity and movement on a monitor or motion detector. This test is usually conducted over several weeks to objectively determine how much a patient is sleeping.

There are a number of ways to treat insomnia. Underlying medical, neurological and mental health conditions may be treated if they are determined to be the cause of sleep disorders.

In some cases, transient (short-term) insomnia does not require treatment. For example, insomnia caused by jet lag will disappear when the body naturally readjusts to time differences after a flight.

Insomnia can sometimes be treated or prevented by making the following lifestyle changes:

• Avoid caffeine and alcohol. Foods and drinks that contain caffeine, such as coffee, tea, some soft drinks and chocolate, should be avoided during the afternoon and evening. Alcohol speeds the onset of sleep but increases waking during the later half of the night.
  
  
• Avoid eating or drinking too close to bedtime. This can interrupt sleep. Also, avoid foods that may cause heartburn, such as tomato products and spicy foods. Lying down worsens heartburn and makes falling asleep more difficult.
  
  
• Avoid smoking. Cigarettes contain nicotine, which has been linked to difficulty falling asleep and problems awakening. Also, when smokers fall asleep, they experience nicotine withdrawal, which may cause them to awaken.
  
  
• Exercise. Exercising 20 to 30 minutes a day often helps people sleep, although exercising too close to bedtime can cause difficulties falling asleep.
  
  
• Find the right temperature for sleeping. Extreme temperatures can disrupt sleep.
  
  
• Get light exposure at the proper times. Too little exposure to sunlight during the day can cause sleep problems at night. In addition, bedrooms should be kept dark during sleeping hours so light does not interfere with slumber.
  
  
• Control noise. Environmental noise can be minimized with ear plugs, rugs, heavy curtains, double-pane windows or white-noise machines.
  
  
• Get a good mattress. Mattress quality can affect sleep quality.
  
  
• Use the bed only for sleep and sex, not for reading, eating or television viewing.
  
  
• Get into bed only when tired.
  
  
• Maintain consistent sleep and wake times.
  
  
• Avoid or regulate nap times. Daytime naps may interfere with nighttime sleeping. Avoid naps or restrict nap times to 20 or 30 minutes.
  
  
• Practice relaxation techniques before bedtime. These may include hot baths, gentle music, meditation or prayer.

Other techniques that may be used to prevent or treat sleep disorders include:

• Relaxation therapy. Methods such as progressive muscle relaxation, deep breathing techniques, imagery and self-hypnosis may help some people overcome sleep disorders.
  
  
• Sleep restriction therapy. Consists of restricting the amount of time spent in bed to increase the percentage of time asleep. Poor sleepers often increase their time spent in bed in an effort to increase sleep time, a strategy that often results in fragmented or poor quality sleep.
  
  
• Stimulus control therapy. Involves reassociating the bed and bedroom with the rapid onset of sleep. It may involve going to bed only when sleepy, using the bed and bedroom only for sleep and sex, getting out of bed and going into another room when unable to sleep and returning to bed only when sleepy again.
  
  
• Cognitive behavioral therapy (CBT). This may help patients identify thoughts and behaviors that contribute to sleep problems. Various studies have shown CBT to be highly effective in alleviating insomnia, especially in older adults.

Medications are sometimes used to treat sleep disorders. They include:

• Non-benzodiazepine hypnotics. Although not chemically like benzodiazepines, they appear to act by binding to receptors in the brain that cause sedation, thereby inducing sleep. They can be used to treat transient or chronic insomnia.
  
  
• Over-the-counter (OTC) sleeping pills. There are numerous OTC sleeping pills available at pharmacies and other stores. Many of these drugs contain antihistamines, which induce drowsiness. However, health experts generally recommend avoiding the use of OTC sleeping pills, especially for long periods of time, because they may have undesired side effects (e.g., dizziness, prolonged drowsiness), tend to lose their effectiveness over time, and may interact with other medications currently being taken by the patient.
  
  
• Melatonin. Hormone produced by the pineal gland during the dark hours of the day-night cycle (circadian rhythm). It promotes the onset of sleep and helps normalize circadian rhythm disorders. Melatonin is sold as a supplement in the United States, which means it is not regulated by the U.S. Food and Drug Administration. Most studies have shown melatonin to have limited benefit for alleviating either transient insomnia (e.g., jet lag) or chronic insomnia.
  
  
• Herbal supplements (e.g., chamomile, valerian). The use of herbal supplements has yet to be fully studied for safety or effectiveness in the treatment of insomnia.

Preparing questions in advance can help patients have more meaningful discussions with their physicians regarding their conditions. Patients may wish to ask their doctor the following questions about insomnia:

1. I have trouble falling asleep sometimes. Do I have insomnia?
   
   
2. I need only four hours of sleep a night to feel rested. Does that mean I have insomnia?
   
   
3. I often have difficulty sleeping at night, but I don't feel tired during the day. Do I still have insomnia?
   
   
4. What may be causing my insomnia?
   
   
5. Could my insomnia be related to another underlying condition?
   
   
6. How might insomnia affect my health?
   
   
7. What are some ways in which I can treat my insomnia?
   
   
8. Can I become addicted to medications for insomnia?
   
   
9. Can my insomnia be prevented?
   
   
10. Do I need to make any lifestyle modifications while undergoing treatment for my insomnia?
    
    
11. How long will it be before I see improvement from my insomnia?