Why WASO Has a Negative Effect on Sleep Quality

If you’ve ever woken up during the middle of the night, you’ve experienced the bothersome condition known as “wakefulness after sleep onset,” which is largely known by the abbreviation WASO.

Get the facts about WASO, its impact on sleep quality and the individuals it’s most likely to affect with this review of the health problem.

A women suffering from insomnia.
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How Researchers Use WASO in Sleep Studies

Medical researchers and sleep clinicians often use the term WASO in sleep studies to define the amount of time test subjects have spent awake after initially falling asleep and before they awaken for good. For example, an individual may go to bed at 11:30 p.m. and suddenly rouse from slumber at 2:30 a.m. and remain awake until 3:45 a.m. tossing and turning.

Perhaps the person awakened to use the bathroom but couldn’t fall asleep again immediately after he finished, or perhaps he awakened because he was hot or simply anxious about the events that transpired the day before or that he expected to transpire the following day. After awakening in the middle of the night, the individual finally falls back asleep and gets up for good at 6:30 a.m. to get the day started.

If this had occurred during a sleep study, the person would have been told that his WASO was 1 hour and 15 minutes on that particular night.

Because he woke up during the middle of the night, he ultimately got a total of five hours and 45 minutes of sleep. That’s less than the National Sleep Foundation’s recommendation that adults up to the age of 64 get seven to nine hours of sleep per night. As a result, the individual who stayed up for more than an hour during the night may not feel energized and refreshed upon waking for good but tired and sluggish.

Which People Are Most Likely to Experience WASO?

People who have difficulty staying asleep are most likely to experience WASO. These individuals may suffer from sleep disorders such as sleep apnea or insomnia or medical conditions such as restless leg syndrome, arthritis, or heart disease. Women who wake up during the night may be undergoing hormonal changes caused by pregnancy or menopause.

Others who wake up during the night may have difficulty sleeping through the night without making a trip to the bathroom. Older people often have this problem, as do people with a variety of medical conditions. Sleep apnea is a common cause of this nocturia. Individuals who suffer from anxiety or who are dealing with stressful situations at home or at work may also have difficulty sleeping through the night.


Because WASO results in poor sleep efficiency, or the time spent sleeping divided by the total time spent in bed, it’s important to counteract the condition, if possible. In those with insomnia, WASO may be improved with a treatment called sleep restriction, a kind of behavioral therapy. This helps to better match the time spent in bed to the sleep ability, or sleep need, which varies some with age.

Insomnia patients who use sleep restriction work to improve their sleep efficiency. Accordingly, they don’t allow themselves to spend hours tossing and turning in bed. Instead, they get out of bed after 15 minutes of wakefulness and go to another room until they feel ready to fall asleep again. This helps to improve conditioning and relieves pressure to sleep or anxiety about sleeping. These patients may also keep a sleep log to record the amount of time they sleep, are awake, and spend in bed. These changes may be incorporated into a cognitive behavioral therapy for insomnia (CBTI) program, the preferred treatment for chronic insomnia.

A Word From Verywell

If you think you’re spending too much time awake during the night, consult your primary care provider or a board-certified sleep physician to pinpoint the most effective ways to treat the problem or to determine if a medical condition, prescription drug or lifestyle habit might be a factor. Simple changes may help to optimize the quality of your sleep and reduce the time spent awake at night.

2 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Ohayon M, Wickwire EM, Hirshkowitz M, et al. National Sleep Foundation's sleep quality recommendations: first report. Sleep Health. 2017;3(1):6-19. doi:10.1016/j.sleh.2016.11.006

  2. Qaseem A, Kansagara D, Forciea MA, Cooke M, Denberg TD; Clinical Guidelines Committee of the American College of Physicians. Management of chronic insomnia disorder in adults: a clinical practice guideline from the American College of Physicians. Ann Intern Med. 2016;165(2):125-133. doi:10.7326/M15-2175

By Brandon Peters, MD
Brandon Peters, MD, is a board-certified neurologist and sleep medicine specialist.