Step 1 of 11
Presentation & Red-Flag Triage
Nocturnal · daytime · paediatric symptoms + safety/cardiopulmonary emergencies
Sleep-disordered breathing presents along a spectrum. Nocturnal symptoms include loud habitual snoring, witnessed apneas, gasping or choking, restless sleep, frequent awakenings, nocturia, and bruxism. Daytime symptoms are excessive sleepiness, fatigue, morning headache, cognitive and memory impairment, mood change, and reduced productivity. In children, snoring, mouth-breathing, hyperactivity, learning and behavioural difficulty, growth impairment, and enuresis predominate.
Before the routine pathway, screen for the situations that demand urgent action: severe hypersomnolence affecting driving or occupational safety (professional drivers, pilots, machine operators); obesity hypoventilation with hypercapnic respiratory failure; pulmonary hypertension or cor pulmonale; severe oxygen desaturation; and uncontrolled cardiovascular disease. These warrant urgent sleep-medicine evaluation, expedited polysomnography, and early PAP rather than a routine wait-listed study.
- Nocturnal — loud snoring, witnessed apnea, gasping/choking, nocturia, restless sleep
- Daytime — excessive sleepiness, fatigue, morning headache, cognitive/mood change
- Paediatric — snoring, mouth-breathing, hyperactivity, learning/behaviour, growth, enuresis
- Safety emergency — severe sleepiness + driving/occupational risk → urgent
- Cardiopulmonary emergency — OHS, hypercapnic failure, pulmonary HTN, cor pulmonale → expedited PSG ± PAP
Key statistics
Moderate-to-severe SDB prevalence
13% / 6%
In population data, moderate-to-severe sleep-disordered breathing (AHI ≥15) affects roughly 13% of men and 6% of women aged 30–70 — a high-burden, under-recognised disease.
★ High-yield pearls (chapter-wide)
- OSA is a chronic, heterogeneous, lifelong disease — the goal is symptom, quality-of-life, and cardiometabolic improvement, not just a normalised AHI.
- Severe sleepiness in a professional driver or machine operator is a safety emergency — counsel on driving and expedite testing and PAP.
- Screen for obesity hypoventilation in any patient with BMI ≥30, severe OSA, and morning headaches — a raised serum bicarbonate or awake PaCO₂ >45 mmHg confirms it and changes management to NIV.
- Home sleep apnea testing suits high-probability uncomplicated OSA only — heart failure, neuromuscular disease, suspected central apnea, or another sleep disorder mandate in-laboratory PSG.
- A negative home study with persistent strong suspicion is not the end — proceed to full PSG; consider UARS and primary snoring.
- Phenotype before you treat — anatomical collapse responds to ENT-directed and device therapy, while high loop gain, a low arousal threshold, or poor muscle compensation need precision strategies.
- Drug-induced sleep endoscopy guides surgery and hypoglossal-nerve-stimulation candidacy — complete concentric palatal collapse contraindicates current HGNS.
- CPAP only works when worn — monitor adherence objectively and run the rescue pathway (mask, pressure, nasal, psychological, social) before declaring failure.
- Paediatric OSA is first treated by adenotonsillectomy when adenotonsillar hypertrophy is present — reassess for residual disease afterwards.
Evidence base
3 sources- HIGH
Kapur VK, Auckley DH, Chowdhuri S · J Clin Sleep Med · 2017AASM guidelinePMID 28162150
AASM guideline on HSAT vs in-laboratory PSG and the indications for each — anchors test selection and interpretation.
- HIGH
Peppard PE, Young T, Barnet JH · Am J Epidemiol · 2013EpidemiologyPMID 23589584
Contemporary population prevalence of sleep-disordered breathing — anchors the burden and severity context.
- HIGH
McEvoy RD, Antic NA, Heeley E · N Engl J Med · 2016Randomized controlled trialPMID 27571048
SAVE trial of CPAP and cardiovascular outcomes — anchors the cardiometabolic risk framing and adherence emphasis.
Decision tree
The triage screen is the first gate. Classification routes the stable patient to one of the aetiology-keyed pathways below. Cross-cut cards capture the chapter's must-not-miss rules.