Upper airway resistance syndrome

Synonyms: UARS

Medical Specialties: Family practice, Pulmonology, Other

Clinical Definition

Upper airway resistance syndrome is a sleep breathing disorder in which resistance to airflow in the upper airway occurs and causes increased workload and frequent respiratory effort-related arousals. It is also one cause of daytime somnolence. Unlike obstructive sleep apnea, it does not cause periods of hypoxia or apnea.  

In Our Own Words

Upper airway resistance syndrome (UARS) is not quite the same as snoring or sleep apnea, but all three conditions have common ground. In people with upper airway resistance syndrome, their air passageway narrows and may collapse slightly, instead of staying completely open. This forces the patient to work harder to pull air into the lungs, which also causes him or her to wake up frequently. Since sleep is interrupted repeatedly, daytime sleepiness may occur.


Upper airway resistance syndrome is not the same thing as sleep apnea, which causes breathing to stop and oxygen levels in the body to drop. Although people who snore may well go on to develop the sleep disruption of UARS or even the drop in oxygen of obstructive sleep apnea, not all snorers have these conditions, and not everyone with these conditions necessarily experiences snoring.

Relevant Conditions
Side Effects
  • Daytime sleepiness
  • Chronic fatigue
  • Snoring
Share this article
  • Ohio Sleep Medicine Institute. “Upper Airway Resistance Syndrome.” http://www.sleepmedicine.com/disorders.cfm?disorder=uars. Accessed September 2013.
  • Center for Sound Sleep. “Learn more about upper airway resistance syndrome.” http://www.centerforsoundsleep.com. Accessed October 2013.
  • Cleveland Clinic. “Sleep-Disordered Breathing.” http://www.clevelandclinicmeded.com. Accessed September 2013.
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