The Takeaway 

Insomnia is a report of difficulty falling asleep, staying asleep at night, or waking up too early. It is associated with impairment in daytime functioning.

Chronic insomnia must be present for at least 3 months and last for 3 or more days of the week. In contrast, acute or transient insomnia will last for only a few days or weeks. However, you can reach out to your provider as early as a month with persisting symptoms. Insomnia is a report of difficulties with one or more of the following:

  • Lying awake in bed for a long time before sleep. More common in young adults.1
  • Fragmented sleep. More common in older adults. There may be more frequent mid-sleep waking throughout the night or time lying awake in bed.1
  • Early wake-time with an inability to go back to sleep.
  • Lack of quality sleep leading to feelings of being unrested, fatigued, irritable, depressed, and reduced ability to concentrate and perform daytime activities.
  • Symptoms persist despite using common strategies to improve sleep see Healthy Sleep Tips

These symptoms are present even when you have the appropriate time and place to sleep. This differs from sleep deficiency. See below for more information.

Know the Difference

Although sleep deficiency and insomnia are used interchangeably, they are not the same. For insomnia, these symptoms are present even when you have the appropriate time and place to sleep. Although fatigued and tired, persons with insomnia are generally unable to nap during the day. This differs from sleep deficiency, which is an inadequate amount of sleep because of lack of time to sleep or a personal decision not to sleep. Sleep deficiency may be caused by an acute stressor like travel or an upcoming deadline that reduces the amount and quality of sleep. Persons who are sleep deficient will easily fall asleep when given the opportunity to do so.

Know the Difference: Insomnia vs. Sleep Deficiency



1. . National Heart Lung and Blood Institute, U.S. Department of Health and Human Services.