Upper airway resistance syndrome (UARS) is a sleep disorder characterized by an obstruction or narrowing of the upper airway, the passage extending from the nose to the esophagus, during sleep. This resistance requires the diaphragm and chest muscles to work harder to breathe. The effort that results from such labored breathing can cause frequent bouts of night waking and difficulty reaching deeper stages of sleep, such as rapid-eye movement (REM) sleep.
UARS is often considered a member of the spectrum of disorders known as sleep-disordered breathing (SDB); the most commonly recognized disorder in this spectrum is obstructive sleep apnea. Although upper airway resistance syndrome is sometimes confused with sleep apnea, it is a very different disorder. In sleep apnea, individuals may stop breathing completely many times throughout the night and will show decreased oxygen levels as a result. Upper airway resistance syndrome, on the other hand, does not cause complete cessation of breathing, and does not necessarily cause decreased oxygen levels, but rather is generally characterized by increased difficulty breathing due to airway restriction.
Common symptoms of upper airway resistance syndrome include chronic fatigue, chronic night waking with difficulty resuming sleep, heavy snoring, and cold hands and feet. Both low blood pressure and hypertension can also be seen. In some cases, the fatigue caused by frequent bouts of night waking in UARS patients is severe enough to interfere with daily function, resulting in reduced productivity at work and in daily life.
Upper airway resistance syndrome patients are often of average build, and obesity is not as prominent a cause as it is in sufferers of other sleep disorders like sleep apnea. Reportedly, more than half of those suffering from the disorder are women, and many are between the ages of 30 and 60. The reduced breathing capabilities experienced as a result of UARS may be caused by another underlying condition, such as chronic nasal obstruction due to allergic rhinitis, deviated septum, or even nasal tumors. Often, UARS patients may already have an airway that is smaller than average; such patients often have delicate features that include a narrow face, small or narrow jaw, thin neck, or other such characteristics that may result in narrowed air passages. These smaller features mean that the normal relaxation that occurs in the airway during sleep causes heightened airway restriction that might not necessarily occur in a person whose airway is of average size.
This condition can be difficult to diagnose without the correct tools. On the surface, its symptoms may mirror those of other, non-sleep-related disorders such as chronic fatigue syndrome, hypothyroidism, or depression. The best way for a patient to obtain an accurate diagnosis of upper airway resistance syndrome is to consult a polysomnologist, or a sleep clinic. Such professionals will have the appropriate tools to test for pressure changes in the nose, alterations in breathing, or pulse wave signals during sleep that would indicate the probably of upper airway resistance syndrome.
UARS is treatable through a number of techniques, including over-the-counter remedies such as breathe strips, nasal dilators, or nasal sprays. Using a continuous positive airway pressure (CPAP) device or oral appliances may also help. Patients should consult a sleep specialist or a physician in order to make an accurate diagnosis and to develop an appropriate treatment plan.