Insomnia is defined as inadequate or poor-quality sleep despite having adequate time to sleep. Insomnia may take the form of difficulty falling asleep, or middle-of-the-night or early-morning awakening. It may be a short-term problem or occur more often over a long period of time. It becomes more common as you get older.
Over the course of a year, about one third to one half of adults experience some level of insomnia. About 10%-15% have more severe or chronic insomnia. It may cause problems during the day, such as tiredness, a lack of energy, difficulty concentrating, and irritability.
Insomnia is not a disease. Instead, it is a result of a behavior or a symptom of an underlying mental or physical problem. There are many causes of insomnia.
Short-term insomnia is often due to temporary situations. It generally occurs in people who are experiencing one or more of the following:
- A life crisis or stress
- A change in the sleep environment, including factors such as noise, light, or temperature
- Sleep/wake schedule problems such as with jet lag or temporary shift work
- Side effects of medication
Chronic insomnia often results from a medical condition. Examples include:
- Manic disorders
- Conditions that cause chronic pain
- Kidney disease
- Heart failure
- Sleep apnea
- Restless legs syndrome
- Parkinson's disease
- Dementia or Alzheimer disease
- Gastroesophageal reflux disease (GERD)
- Sickle cell disease
Chronic insomnia may caused by lifestyle or behavioral factors. These may include:
- Misuse of nicotine, caffeine, alcohol, or other substances
- Disrupted sleep/wake cycles from shift work or other nighttime activity schedules
- Chronic stress
For some people, insomnia is aggravated by 2 common responses:
- Expecting to have difficulty sleeping and worrying about it, or
- Excessive napping in the afternoon or evening
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Insomnia. National Heart, Lung, and Blood Institute website. Available at: https://www.nhlbi.nih.gov/health-topics/insomnia. Accessed March 6, 2018.
Insomnia. National Sleep Foundation website. Available at: https://sleepfoundation.org/insomnia/home. Accessed March 6, 2018.
Insomnia in adults. EBSCO DynaMed Plus website. Available at:http://www.dynamed.com/topics/dmp~AN~T114839/Insomnia-in-adults. Updated June 5, 2017. Accessed March 6, 2018.
Last reviewed March 2018 by EBSCO Medical Review Board Monica Zangwill, MD, MPH Last Updated: 3/15/2015