Scope & epidemiology

OSA affects 9–38% of adults depending on definitions and populations; prevalence increases with age, male sex, obesity and craniofacial risk factors. Untreated OSA is linked to hypertension, cardiovascular disease, metabolic dysfunction, daytime sleepiness and impaired quality of life.

Pathophysiology & risk factors

• Intermittent upper airway collapse during sleep — anatomical (neck circumference, mandibular anatomy) and functional (reduced neuromuscular tone) factors.
• Risk factors: obesity, male sex, age, family history, alcohol/sedative use, nasal obstruction, hypothyroidism, and craniofacial abnormalities.

Clinical features

• Loud habitual snoring, witnessed apneas or gasping, unrefreshing sleep, excessive daytime sleepiness, morning headache, nocturia, and cognitive impairment.
• Physical signs: high BMI, large neck circumference (>40 cm), crowded oropharynx, nasal obstruction.

Screening & assessment

1. Use validated questionnaires (STOP‑BANG, Epworth Sleepiness Scale) to estimate pretest probability.
2. Take a focused sleep history: bed partner observations, daytime function, comorbidities and medication/substance use.
3. Examine ENT and airway anatomy; consider awake endoscopy or imaging in complex cases.

Diagnostic testing

• Polysomnography (PSG): gold standard — measures apneas/hypopneas, oxygen desaturation, arousals and sleep architecture. Report AHI (apnea–hypopnea index) and oxygen metrics.
• Home sleep apnea testing (HSAT): acceptable for patients with high pretest probability and no significant cardiopulmonary/neurologic comorbidity; HSAT measures respiratory events and oxygen but not sleep stages.
• Severity classification: AHI 5–14 mild, 15–29 moderate, ≥30 severe (interpret alongside symptoms and oxygenation).

Management — general principles

• Treat clinically relevant OSA (symptomatic or with cardiometabolic risk) — tailor therapy to severity, anatomy, comorbidity and patient preference.
• Combine conservative measures (weight loss, positional therapy, alcohol/sedative avoidance) with device or procedural interventions when indicated.

First‑line therapy: Positive airway pressure

• CPAP: gold standard for moderate–severe OSA — titrated to eliminate apneas/hypopneas and desaturation; improves sleepiness, blood pressure and quality of life when used adherently.
• Auto‑PAP (APAP): useful for home titration; often used when pressure requirements are variable or fixed titration unavailable.
• Adherence support is critical: mask fit, humidification, education, follow‑up and behavioural interventions increase usage.

Oral appliances & positional therapy

• Mandibular advancement devices (MAD): effective for mild–moderate OSA or CPAP intolerance — advance mandible to open airway; custom devices by dental sleep specialists preferred.
• Positional therapy: for positional OSA (worse supine) — devices or behavioural strategies to promote side‑sleeping; combine with other treatments where needed.

Surgical & procedural options

• Uvulopalatopharyngoplasty (UPPP), tonsillectomy (in selected patients), maxillomandibular advancement (MMA), hypoglossal nerve stimulation (implantable), nasal surgery to improve CPAP tolerance — selection depends on anatomy and prior therapy response.
• Hypoglossal nerve stimulation: option for selected CPAP‑intolerant patients with moderate–severe OSA and specific criteria (BMI limits, no complete concentric collapse at palate on DISE).
• Consider multilevel surgical assessment with drug‑induced sleep endoscopy (DISE) for refractory cases.

Adjunctive and lifestyle measures

• Weight reduction (5–10% weight loss reduces OSA severity), exercise, avoidance of alcohol or sedatives before bedtime, and smoking cessation.
• Address nasal obstruction and treat comorbid conditions (hypothyroidism, heart failure) that may worsen OSA.

Key takeaways

• Recognise OSA by snoring, witnessed apneas and daytime sleepiness; confirm with PSG or HSAT depending on pretest probability and comorbidities.
• CPAP is first‑line for moderate–severe OSA; individualise care with MAD, positional therapy, weight loss, or surgery when appropriate and support adherence actively.
• Address cardiovascular and metabolic comorbidities and refer early for complex or high‑risk cases.