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.
Over the course of a year, about one third 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 those due to jet lag or temporary shift work
- Side effects of medication
Chronic insomnia often results from a medical condition. They may include: