Upper Airway Resistance Syndrome

What Is UARS?

Upper Airway Resistance Syndrome (UARS) is a sleep-related breathing disorder first described by Dr. Christian Guilleminault in 1993. Your airway narrows during sleep, increasing the effort required to breathe. This effort triggers micro-arousals — your brain briefly waking you to breathe harder — without the oxygen drops that define conventional sleep apnea.

Because standard sleep studies measure apnea-hypopnea index (AHI) — the number of complete or near-complete airway obstructions per hour — UARS gets missed. Your AHI can be completely normal while your respiratory disturbance index (RDI) is significantly elevated. Most doctors only look at AHI.

Why It Gets Dismissed

UARS doesn't fit the traditional sleep apnea profile. The typical UARS patient is young, normal weight, and doesn't snore loudly. That's the opposite of the "sleep apnea" mental model most GPs carry. Add in that the symptoms — chronic fatigue, brain fog, anxiety, cold hands and feet, morning headaches — overlap with depression, anxiety, and chronic fatigue syndrome, and you have a condition primed for misdiagnosis.

"I was laughed out of the office. I was told there was no way — I didn't fit the profile."

The Nervous System Connection

UARS doesn't just disrupt sleep — it activates the sympathetic nervous system repeatedly through the night. Every micro-arousal is a small stress response. Over years, this creates a baseline of autonomic nervous system dysregulation: chronically elevated arousal, reduced vagal tone, and a body that has learned that sleep is dangerous.

When UARS co-occurs with CPTSD — as it often does, because childhood trauma lowers the arousal threshold that makes UARS worse — the two conditions create a self-reinforcing loop that mechanical treatment alone often can't fully resolve.

Common Misdiagnoses

• Anxiety or panic disorder
• Depression
• Fibromyalgia
• Chronic fatigue syndrome / ME
• Undifferentiated connective tissue disease
• "Normal" sleep study — no further investigation

Key Numbers to Know

• AHI — Apnea-Hypopnea Index. What most doctors look at. Can be normal (under 5) in UARS.
• RDI — Respiratory Disturbance Index. Includes RERAs. This is what matters for UARS.
• RERA — Respiratory Effort-Related Arousal. The hallmark of UARS. Often not reported on standard studies.
• Arousal index — More than 15 arousals/hour with normal AHI = classic UARS pattern.

Treatment Options

Treatment for UARS ranges from conservative to surgical, depending on anatomy and severity:

• Positional therapy — many UARS patients are worse on their back
• Nasal dilators, mouth tape — improve nasal airflow
• Myofunctional therapy — addresses tongue posture and oral function
• CPAP / BiPAP — often at lower pressures than OSA; compliance can be challenging
• Oral appliance (MAD) — mandibular advancement, good for anatomy-related UARS
• Surgery — palate expansion (MSE/EASE), maxillomandibular advancement (MMA/DJS), soft tissue procedures

Important: even after successful mechanical treatment, nervous system recalibration takes time. The body needs to re-learn that sleep is safe. This is why some people still struggle after surgery.