Sleep-related breathing disorders
Upper Airway Resistance Syndrome
Increased effort to breathe through a narrowed airway causes repeated brief awakenings and daytime fatigue, without full apneas or major oxygen drops.
Overview
Upper airway resistance syndrome (UARS) describes people whose airway narrows during sleep enough to make breathing harder and trigger brief arousals, but not enough to cause the full apneas and oxygen drops counted in a standard sleep apnea diagnosis. These events are called respiratory effort-related arousals (RERAs).
People with UARS are often younger and slimmer than typical OSA patients and may report fatigue, unrefreshing sleep, insomnia, headaches or anxiety more than classic sleepiness. Snoring may be present or absent.
Current international sleep classification groups UARS within obstructive sleep apnea rather than as a separate diagnosis, and specialists continue to debate how best to define it. If you have symptoms and a home test was normal, it is reasonable to ask whether a full in-lab study is needed.
Common symptoms
- Chronic fatigue and unrefreshing sleep
- Frequent awakenings or difficulty staying asleep
- Daytime sleepiness or brain fog
- Morning headaches
- Snoring or noisy breathing (not always present)
- Cold hands and feet or lightheadedness when standing, reported by some patients
Causes and risk factors
- Narrow upper airway or small jaw
- Nasal obstruction, deviated septum or chronic congestion
- Large tonsils or adenoids
- Sleeping on your back
- Alcohol before bed
How it is diagnosed
UARS is usually suspected when someone has symptoms of disrupted sleep but a home sleep test is normal. An in-lab polysomnogram with sensitive airflow measurement, such as a nasal pressure sensor, can detect flow limitation and RERAs.
Results may be reported as a respiratory disturbance index (RDI), which counts apneas, hypopneas and RERAs together. A clinician interprets this alongside your symptoms and examination, since scoring rules for RERAs vary between labs.
Treatment options
CPAP
Low-pressure CPAP can eliminate flow limitation and arousals.
Oral appliance
Advancing the jaw can open the airway in suitable people.
Treating nasal obstruction
Medical treatment of congestion or nasal surgery may help when the nose is the main problem.
Positional therapy
Avoiding sleeping on your back may reduce events.
Airway surgery
Selected people may benefit, though evidence is limited.
What you can do yourself
- Keep a sleep diary and note how you feel each morning
- Treat allergies and nasal congestion
- Avoid alcohol and sedatives before bed
- Try side sleeping
- Keep a regular sleep schedule
When to see a doctor
- You feel exhausted despite enough time in bed and a normal home sleep test
- You wake frequently without a clear reason
- You have daytime sleepiness that affects driving or work
Frequently asked questions
Can a home sleep test miss UARS?
Yes. Most home sleep apnea tests do not record brain activity, so they cannot detect the brief arousals that define RERAs. An in-lab polysomnogram is usually needed when UARS is suspected.
What is RDI versus AHI?
AHI counts apneas and hypopneas per hour of sleep. RDI adds respiratory effort-related arousals, so it can be higher than the AHI in people with UARS.
Is UARS a real diagnosis?
The symptoms and sleep study findings are real, but current international classification places UARS under obstructive sleep apnea rather than as its own disorder. Clinicians still use the term to describe this pattern.
Does CPAP help UARS?
Many people with UARS respond to CPAP, often at relatively low pressure. Some find it hard to tolerate, and oral appliances or nasal treatment are alternatives.
Sources
This page is general information, not a diagnosis or medical advice. Read our medical disclaimer.