Overview
Obstructive Sleep Apnoea
1. Clinical Overview
Summary
Obstructive sleep apnoea (OSA) is characterised by recurrent upper airway obstruction during sleep, causing apnoeas/hypopnoeas, oxygen desaturation, and sleep fragmentation. Presents with snoring, witnessed apnoeas, and excessive daytime sleepiness. Diagnosis is by sleep study (polysomnography or home oximetry/polygraphy). Severity is graded by Apnoea-Hypopnoea Index (AHI). CPAP is first-line treatment for moderate-severe OSA. Risk factors include obesity, male sex, and structural airway abnormalities.
Key Facts
- Definition: Recurrent upper airway obstruction during sleep
- Prevalence: 4-7% of adult population
- Risk factors: Obesity (strongest), male, middle-age, craniofacial abnormality
- Diagnosis: AHI from sleep study
2. Classification
| Severity | AHI (events/hour) |
|---|---|
| Mild | 5-14 |
| Moderate | 15-29 |
| Severe | 30+ |
3. Management
Lifestyle
- Weight loss (most effective modifiable factor)
- Avoid alcohol and sedatives
- Sleep positioning
CPAP
- First-line for moderate-severe OSA
- Splints airway open
- DVLA implications until symptoms controlled
Other
- Mandibular advancement device (mild-moderate)
- Surgery (rarely)
4. References
- NICE Technology Appraisal TA139. CPAP for OSA. 2008.
Last Reviewed: 2026-01-01 | MedVellum Editorial Team