Reviewed by Dr. Harrington

Although sleep is an essential part of life, for many people restful sleep is elusive. Insomnia, the most common sleep disorder, includes having difficulty falling asleep, waking often during the night, waking up too early, or just feeling that your sleep isn't refreshing.

Almost everyone has insomnia sometimes. But it can be a chronic problem that has a major impact on how you function during the day. It can make you irritable, impair your judgment, and increase your risk of accidents by making you less alert during the day. It also can worsen existing medical problems and lead to new ones.

Insomnia should not be ignored or dismissed as merely a nuisance. Those who seek treatment can get relief. First, there is a lot you can do at home to improve your chances of getting a good night's sleep. Also, a variety of therapies can help, as can new drugs that make it easier for insomnia sufferers to fall asleep and stay asleep. Common symptoms include difficulty sleeping, excessive sleepiness or fatigue during the day, irritability, morning headaches, and poor attention.


Severity of Insomnia

There are varying degrees of severity for insomnia.

  • Mild Insomnia: Poor sleep has little effect on social function or work.
  • Moderate Insomnia: Poor sleep impacts social and work function.
  • Severe Insomnia: Poor sleep has a major impact on how a person functions during the day.
  • Acute Insomnia: Poor sleep lasts only a few days.
  • Chronic Insomnia: Poor sleep may last for several months or more. It may start in early childhood and be life-long.

Most people have had difficulty sleeping at some point. A national survey indicated that 35%* of adults reported having insomnia over the previous year. Insomnia symptoms can include difficulty falling asleep, staying asleep, frequent awakenings during sleep or early morning awakening. This can cause many problems during the waking hours that can affect daily function. Insomnia can happen for short periods of time (days to weeks) or can be chronic (month or longer).

To learn more about symptoms, causes, dangers and treatment view the patient information from the American Thoracic Society’s Patient Information series on Insomnia.

* Information and statistics have been provided by the American Thoracic Society.


National Jewish Health experts provided information on this topic for use on the U.S. News & World Report website.

Programs & Services

Clinical Trials

Insomnia and Daytime Functioning

The purpose of this study is to learn more about people with primary insomnia and cognitive impairment. Primary insomnia is having difficulty falling asleep or staying asleep despite adequate opportunity for sleep, and your insomnia is not directly associated with any other health condition or problem. Cognitive impairment is difficulty with mental abilities such as thinking, knowing and remembering.

If you decided to participate in this study, you would be assigned to either the primary insomnia group or normal sleeper group based on your responses to our study questionnaires. You will then be asked to perform 2 consecutive nights of home sleep testing, followed by a daytime Multiple Sleep Latency Test (MSLT) at National Jewish Health’s Sleep Lab. The MSLT study is a daytime sleep study and includes a series of naps spaced about 2 hours apart from each other. We have you try to fall asleep during each nap in an effort to try and see how long it takes you to fall asleep. If you do fall asleep we will give you 20 minutes to sleep and look for a type of sleep called Rapid Eye Movement or REM sleep before we wake you up. In between the naps we will ask you to complete neuro-cognitive tests that will examine your memory and concentration. The MSLT testing will take place during the day at National Jewish Health and will last all day from 7am-5 pm. 


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