Upper Airway Resistance Syndrome (UARS)

What is Upper Airway Resistance Syndrome?

Upper Airway Resistance Syndrome (UARS) is a sleep-related breathing disorder that sits on the spectrum between primary snoring and obstructive sleep apnea. In UARS, the airway narrows during sleep, creating increased resistance to breathing—but without the complete or near-complete airflow stoppages that define sleep apnea.

Despite the absence of frank apneas, UARS causes significant sleep fragmentation and can be just as debilitating as sleep apnea in terms of daytime symptoms.

Understanding the UARS Spectrum

Sleep-disordered breathing exists on a continuum:

1. Primary Snoring: Noise during sleep, minimal sleep disruption
2. UARS: Increased airway resistance → respiratory effort → arousals
3. Obstructive Sleep Apnea: Complete or partial airway collapse → apneas/hypopneas

UARS occupies the middle ground—more serious than simple snoring but with fewer obvious breathing events than OSA.

How UARS Affects Sleep

The Cycle of UARS

1. Airway Narrowing: During sleep, the airway partially narrows
2. Increased Respiratory Effort: The body works harder to breathe against the resistance
3. Arousal from Sleep: This effort triggers brief awakenings (arousals) to restore normal breathing
4. Sleep Fragmentation: These frequent arousals prevent deep, restorative sleep
5. Daytime Consequences: Poor sleep quality leads to severe daytime symptoms

Respiratory Effort-Related Arousals (RERAs)

RERAs are the hallmark of UARS:

• Brief awakenings caused by increased breathing effort
• Occur before breathing stops completely
• May happen dozens or hundreds of times per night
• Prevent progression into deep sleep stages
• Usually not remembered by the patient

Symptoms of UARS

Nighttime Symptoms

• Light, unrefreshing sleep despite adequate time in bed
• Frequent awakenings (though may not be fully conscious)
• Difficulty falling asleep (insomnia)
• Vivid dreams or nightmares from disrupted REM sleep
• Nocturia (frequent nighttime urination)
• Snoring (though often milder than in OSA, sometimes absent)

Daytime Symptoms

• Chronic fatigue and exhaustion
• Difficulty waking up and severe morning grogginess
• Cognitive dysfunction: Poor concentration, memory problems
• Mood disturbances: Anxiety, depression, irritability
• Headaches, especially in the morning
• Low blood pressure (hypotension) in some cases
• Cold hands and feet

Distinguishing Features

• Symptoms often more severe in women and younger, thinner individuals
• May have lower BMI than typical OSA patients
• Often a long history of sleep problems
• May have been misdiagnosed with depression, chronic fatigue syndrome, or fibromyalgia

Who Gets UARS?

Common Characteristics

• Younger adults (20s-40s more common than OSA)
• Women as often as men (unlike OSA which is more common in men)
• Normal or low body weight (unlike OSA which correlates with obesity)
• Smaller jaw or facial structures
• Narrow palate or crowded airway anatomy

Risk Factors

• Anatomical airway narrowing
• Nasal obstruction or deviated septum
• Enlarged turbinates
• Soft palate characteristics
• Jaw position and structure

Diagnosis of UARS

Why UARS is Often Missed

Standard home sleep tests (HSAT) typically don’t capture the measurements needed to diagnose UARS:

• HSATs measure airflow, oxygen, and basic breathing
• They usually don’t measure respiratory effort
• RERAs may not be detected

Proper Diagnosis Requires:

In-Lab Polysomnography:

• Full overnight sleep study in a lab
• Esophageal pressure monitoring (gold standard for measuring respiratory effort)
• EEG to detect micro-arousals
• Comprehensive respiratory measurements

Physician Interpretation: Sleep apnea and UARS must be diagnosed by a physician, typically a sleep medicine specialist.

Important: We coordinate with physicians who can order appropriate testing, including in-lab studies when UARS is suspected.

Treatment Options for UARS

The goal is to reduce airway resistance and eliminate respiratory effort-related arousals.

Oral Appliance Therapy

Highly effective for UARS:

• Opens the airway by advancing the jaw
• Reduces resistance to breathing
• Eliminates RERAs and allows normal sleep
• Non-invasive and well-tolerated
• Portable for travel

Many patients with UARS respond excellently to oral appliances, often experiencing dramatic symptom improvement.

CPAP Therapy

Can also be effective:

• Provides positive pressure to maintain airway opening
• Reduces respiratory effort
• Eliminates RERAs
• May be recommended for some patients

Surgical Options

Considered in specific cases:

• Nasal surgery for obstruction (deviated septum, turbinates)
• Soft palate procedures
• Jaw advancement surgery for severe anatomical issues

Positional Therapy

If UARS is worse in certain positions:

• Sleeping on side instead of back
• Special pillows or devices
• Can supplement other treatments

Why Treatment is Important

Health Consequences of Untreated UARS

While UARS doesn’t cause the oxygen desaturation events of OSA, chronic sleep fragmentation leads to:

• Cardiovascular stress from repeated arousals
• Autonomic nervous system dysfunction
• Hormonal imbalances from sleep disruption
• Cognitive impairment and memory problems
• Mental health impacts: Depression, anxiety
• Reduced quality of life and functional impairment

Impact on Daily Life

UARS can be severely debilitating:

• Inability to function normally despite “adequate” sleep
• Work performance suffers
• Relationships strained by irritability and fatigue
• Social activities avoided due to exhaustion
• Often misdiagnosed and untreated for years

Our Approach to UARS

Recognition and Screening

We evaluate for UARS when patients present with:

• Chronic unexplained fatigue
• Non-restorative sleep
• Normal or low AHI but significant symptoms
• History suggesting sleep fragmentation

Coordination with Sleep Physicians

We work with physicians to:

• Recommend appropriate testing (in-lab PSG with esophageal pressure)
• Interpret results in context of symptoms
• Plan appropriate treatment

Oral Appliance Therapy

For diagnosed UARS, we provide:

• Custom-fitted oral appliances
• Careful titration to optimal position
• Symptom monitoring
• Follow-up testing to verify improvement

Success with UARS Treatment

Many UARS patients experience remarkable improvement:

• First truly restful sleep in years
• Energy returns within days to weeks
• Cognitive function improves dramatically
• Mood and anxiety improve
• Quality of life transformed

Because UARS often goes undiagnosed for years, finally getting effective treatment can be life-changing.

When to Suspect UARS

Consider evaluation if you:

• Are chronically exhausted despite sleeping enough hours
• Wake feeling unrefreshed no matter how long you sleep
• Have had sleep problems for years without clear cause
• Were told you don’t have sleep apnea but still feel terrible
• Have been diagnosed with chronic fatigue or depression without improvement
• Are young, thin, and exhausted with no explanation

Getting Started

If you suspect you might have UARS, proper evaluation is essential. While standard home sleep tests may not detect it, comprehensive assessment and coordination with sleep physicians can lead to diagnosis and effective treatment.

Schedule a consultation to discuss your symptoms and explore whether UARS evaluation is appropriate.

Note: Sleep testing must be ordered and interpreted by a physician. We coordinate testing and provide oral appliance therapy in collaboration with the patient’s sleep physician.