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Obstructive sleep apnoea (OSA) is when the upper airway repeatedly collapses during sleep, briefly stopping breathing and disturbing rest — often without you realising. It causes loud snoring, gasping, daytime sleepiness and poor concentration, and over time raises blood pressure and heart risk. It is diagnosed with a sleep study that measures how often breathing pauses occur. Effective treatments include weight loss, a CPAP machine that keeps the airway open, dental devices and treating the nose. This page explains OSA and how it is managed.
Obstructive sleep apnoea (OSA) is the most common sleep-disordered breathing condition and a frequent and under-recognised driver of cardiovascular disease, refractory hypertension, atrial fibrillation, heart failure, and stroke. Obesity hypoventilation syndrome (OHS) is a distinct but related disorder of awake hypercapnia in obese individuals.
Definition
Obstructive sleep apnoea is recurrent collapse of the upper airway during sleep, causing apnoeas and hypopnoeas with oxygen desaturation and arousal. Severity is graded by the apnoea-hypopnoea index (AHI): mild 5–15, moderate 15–30, severe >30 events per hour.
Obesity hypoventilation syndrome (OHS) is defined by obesity (BMI ≥30), awake hypercapnia (PaCO₂ >45 mmHg) and sleep-disordered breathing, in the absence of an alternative cause of hypoventilation.
Pathophysiology
A combination of anatomical (narrow upper airway, retrognathia, increased neck circumference, fat deposition), neuromuscular (reduced upper airway dilator activity during sleep), and arousal-related factors causes upper airway collapse. Repetitive desaturation, sympathetic activation, and arousal underpin the cardiovascular and metabolic consequences.
Co-morbidities
Hypertension (particularly resistant hypertension), atrial fibrillation, heart failure, stroke, type 2 diabetes, depression, gastro-oesophageal reflux, nocturia, erectile dysfunction, and motor-vehicle accident risk from daytime sleepiness.
Prevalence
OSA affects approximately 20–25% of Australian adults to some degree, with moderate-to-severe disease in 5–10%. Prevalence increases with age, obesity, and male sex (although the male predominance narrows after menopause).
Causes and risk factors
Obesity, male sex, age, post-menopausal status in women, craniofacial structure (small mandible, large tongue, large tonsils, deviated septum), alcohol and sedative use, smoking, nasal obstruction, hypothyroidism, and acromegaly.
Symptoms
Loud habitual snoring, witnessed apnoeas, choking or gasping at night, restless sleep, nocturia, morning headache, dry mouth, excessive daytime sleepiness, fatigue, impaired concentration, mood disturbance, and reduced libido.
Diagnosis
Screening
STOP-BANG, Epworth Sleepiness Scale, OSA-50, and Berlin Questionnaire are commonly used in primary care. High-risk patients (cardiovascular disease, refractory hypertension, AF, heart failure, type 2 diabetes, professional drivers, pre-operative obesity) warrant systematic screening.1
Confirmatory testing
Type 1 in-laboratory polysomnography remains the gold standard. Type 2/3 home sleep studies are increasingly used as the initial investigation for uncomplicated suspected OSA in adults without significant co-morbidity. The Medicare-rebated pathway requires symptom-based and tool-based screening prior to study.
Awake assessment
Examination should include BMI, neck circumference, Mallampati score, examination of the nasal passages, oropharynx, mandibular position, and assessment of nasal patency.
Investigations for OHS
Suspected OHS (BMI ≥30 + daytime sleepiness or hypoxaemia) warrants arterial or venous blood gas (or serum bicarbonate as a screening surrogate), pulmonary function testing, and overnight oximetry with transcutaneous or arterial CO₂ monitoring where available.
Management
Lifestyle and behavioural
Weight reduction (10% reduction in body weight reduces AHI by approximately 25%), bariatric surgery in eligible patients, avoidance of alcohol and sedatives near bedtime, smoking cessation, positional therapy for supine-predominant OSA, treatment of nasal obstruction, and sleep hygiene.2
Continuous positive airway pressure (CPAP)
CPAP is first-line therapy for moderate-to-severe OSA and for symptomatic mild OSA. Adherence is the principal determinant of effectiveness; structured education, mask fitting, humidification, and follow-up improve adherence substantially. APAP (auto-titrating PAP) is widely used as initial therapy.
Mandibular advancement splints
Custom-made mandibular advancement splints are an effective alternative for mild-to-moderate OSA and for patients intolerant of CPAP. Dental review for suitability and follow-up for TMJ effects and dental movement are required.3,4
Surgical and other interventions
Upper airway surgery (uvulopalatopharyngoplasty, maxillomandibular advancement), hypoglossal nerve stimulation (where available), and bariatric surgery in selected patients. Tonsillectomy is the first-line intervention in children with OSA.5
OHS management
Non-invasive ventilation (typically bi-level PAP) is first-line for OHS, with CPAP an alternative for selected stable patients. Weight reduction, including bariatric surgery, is a central component.
Driving and occupational considerations
Untreated OSA with significant daytime sleepiness is a relative contraindication to commercial driving in Australia (Austroads Assessing Fitness to Drive). Documented treatment adherence and resolution of symptoms restore eligibility. Workplace fatigue management plans are relevant for shift workers and heavy-vehicle operators.
Medications
Adjunctive therapy
No medication is first-line for OSA. Wakefulness-promoting agents (modafinil, solriamfetol) are used for residual sleepiness on optimal PAP. Newer pharmacotherapies targeting upper airway tone (atomoxetine plus oxybutynin combinations) are emerging but not yet in routine use. Treatment of contributing conditions (e.g. hypothyroidism, allergic rhinitis) supports overall therapy.6
Multi-system manifestations
Cardiovascular
OSA is independently associated with hypertension, atrial fibrillation, heart failure (both HFrEF and HFpEF), stroke, and pulmonary hypertension. Treatment of OSA improves blood pressure (particularly in resistant hypertension), reduces AF recurrence after cardioversion or ablation, and may improve HF outcomes.7
Metabolic
Insulin resistance, type 2 diabetes, dyslipidaemia, and non-alcoholic fatty liver disease are commonly co-existing and bidirectionally related to OSA.
Neurocognitive and mood
Excessive daytime sleepiness, impaired concentration and memory, mood disturbance, and increased motor vehicle accident risk. Most reverse with effective treatment.
Other
Erectile dysfunction, reduced libido, nocturia, gastro-oesophageal reflux, and peri-operative risk (difficult airway, post-operative respiratory complications).
Living with sleep-disordered breathing
CPAP adherence support
CPAP adherence is the principal determinant of treatment effectiveness. Common issues — mask leak, claustrophobia, dryness, mouth-breathing, pressure intolerance — are usually solvable with structured troubleshooting, mask change, humidification adjustment, and pressure modification. Physiotherapy contributes via breathing pattern work, nasal patency, and oropharyngeal exercises.
Oropharyngeal and breathing exercises
Structured oropharyngeal exercises (tongue, soft palate, and pharyngeal muscle training) reduce AHI modestly in mild-to-moderate OSA. They are useful adjuncts and an option for patients unable or unwilling to use CPAP.8
Weight management and exercise
Weight loss is the single most effective long-term intervention for OSA in overweight or obese patients. Structured exercise improves OSA severity independent of weight loss and improves cardiometabolic risk and daytime sleepiness.9,10
Travel
CPAP machines travel as medical equipment without baggage allowance impact. Portable models and battery packs are available. Patients should travel with a copy of their prescription and replacement supplies.
Prognosis
OSA is generally a lifelong condition that requires ongoing management. Effectively treated OSA carries similar long-term cardiovascular outcomes to the general population in most studies. Untreated severe OSA is associated with substantial excess cardiovascular and all-cause mortality.
Role of the physiotherapist
The physiotherapist supports the practical side of sleep-disordered breathing: CPAP and BiPAP set-up, mask fitting and ongoing monitoring, alongside weight-management support through exercise. They also screen for and treat coexisting breathing pattern disorders and reinforce adherence, which is the main determinant of benefit.
Warning signs
Part 1 · References
- Chung F, Abdullah HR, Liao P. STOP-Bang questionnaire: a practical approach to screen for obstructive sleep apnea. Chest 2016;149(3):631–638.
- Patil SP, Ayappa IA, Caples SM, Kimoff RJ, Patel SR, Harrod CG. Treatment of adult obstructive sleep apnea with positive airway pressure: an American Academy of Sleep Medicine clinical practice guideline. J Clin Sleep Med 2019;15(2):335–343.
- Phillips CL, Grunstein RR, Darendeliler MA, et al. Health outcomes of continuous positive airway pressure versus oral appliance treatment for obstructive sleep apnea: a randomized controlled trial. Am J Respir Crit Care Med 2013;187(8):879–887.
- Bratton DJ, Gaisl T, Wons AM, Kohler M. CPAP vs mandibular advancement devices and blood pressure in patients with obstructive sleep apnea: a systematic review and meta-analysis. JAMA 2015;314(21):2280–2293.
- Strollo PJ Jr, Soose RJ, Maurer JT, et al. Upper-airway stimulation for obstructive sleep apnea (STAR). N Engl J Med 2014;370(2):139–149.
- Malhotra A, Grunstein RR, Fietze I, et al. Tirzepatide for the treatment of obstructive sleep apnea and obesity (SURMOUNT-OSA). N Engl J Med 2024;391(13):1193–1205.
- McEvoy RD, Antic NA, Heeley E, et al. CPAP for prevention of cardiovascular events in obstructive sleep apnea (SAVE). N Engl J Med 2016;375(10):919–931.
- Guimarães KC, Drager LF, Genta PR, Marcondes BF, Lorenzi-Filho G. Effects of oropharyngeal exercises on patients with moderate obstructive sleep apnea syndrome. Am J Respir Crit Care Med 2009;179(10):962–966.
- Foster GD, Borradaile KE, Sanders MH, et al. A randomized study on the effect of weight loss on obstructive sleep apnea among obese patients with type 2 diabetes: the Sleep AHEAD study. Arch Intern Med 2009;169(17):1619–1626.
- Iftikhar IH, Kline CE, Youngstedt SD. Effects of exercise training on sleep apnea: a meta-analysis. Lung 2014;192(1):175–184.
References are numbered in citation order (Vancouver/BMJ style) and were current at the time of writing. Guidelines are living documents — verify against the latest version before clinical use.
More than one of our services applies here, and which combination suits you depends on what your assessment shows.
- Lifestyle Changes Programme — supervised exercise and practical education, aimed at strength and everyday function
- Sleep Apnoea Check — our screening check to take to your GP, who can refer you on for a home sleep study elsewhere
- Oxygen, ventilation & sleep support — CPAP and BiPAP set-up, titration against your prescription, and adherence support once you are diagnosed
Clinical evidence
Part 1 covers the same condition without the technical detail. What follows is the evidence base behind it, written for clinicians — the literature, the reasoning and the gaps.
For clinicians: this summary supports clinical reasoning and is not a protocol. Check current guidelines and local policy before applying it, and read it alongside the key references and guidelines directory.
Framing. Obstructive sleep apnoea is treated for symptoms and function first. CPAP reliably improves sleepiness, quality of life, blood pressure and driving risk, but the large randomised secondary-prevention trial (SAVE) did not show a reduction in cardiovascular events — largely because average adherence was around three hours a night.1,2 That single fact reframes the clinical task: the intervention is adherence, and non-CPAP treatments — weight, exercise, position, oral appliances, upper-airway training — are legitimate rather than second-rate.
Treatment evidence
- CPAP improves sleepiness, quality of life and blood pressure across randomised trials, with effect proportional to hours of use; the practical threshold for meaningful benefit is generally taken as more than four hours a night.1,3
- Mandibular advancement splints produce smaller reductions in apnoea–hypopnoea index than CPAP but comparable improvements in sleepiness and blood pressure, because adherence is higher — a reasonable choice in mild-to-moderate disease or CPAP intolerance.4
- Weight loss reduces severity substantially: intensive lifestyle intervention reduced AHI in obese patients with type 2 diabetes, and greater weight loss produces greater reduction.5
- Tirzepatide reduced AHI by about 25–29 events per hour in obesity-related moderate-to-severe OSA in SURMOUNT-OSA, with improvement in sleepiness and blood pressure — the first pharmacotherapy with a substantial effect on the disorder itself.6
- Exercise training reduces AHI largely independently of weight loss (roughly six events per hour in meta-analysis) and improves sleepiness and fitness — direct evidence for a physiotherapy-deliverable treatment.7
- Oropharyngeal and myofunctional exercises reduced AHI and snoring in randomised trials of moderate OSA, with modest effect sizes and reasonable adherence.8
- Hypoglossal nerve stimulation is an option in selected CPAP-intolerant patients without concentric collapse.9
Physiotherapy implications
- Screen everyone with the relevant risk profile — STOP-Bang or equivalent — because OSA drives resistant hypertension, atrial fibrillation recurrence, poor glycaemic control, daytime injury risk and poor rehabilitation response.10
- Prescribe exercise as OSA treatment, not just as weight management: combined aerobic and resistance training reduces severity even when weight does not change, which is a persuasive message for patients who have failed at weight loss.7
- Address position: in supine-predominant disease, side-sleeping strategies and head-of-bed elevation are simple and effective adjuncts.
- Troubleshoot CPAP practically — mask fit and leak, nasal congestion, humidification, pressure intolerance, claustrophobia, aerophagia — and refer back to the sleep service rather than letting a patient quietly abandon therapy.1
- Ask about driving and occupational safety and know the local fitness-to-drive obligations; untreated significant sleepiness in a commercial driver is a safety issue that must be escalated.10
- Coordinate rather than duplicate: sleep physician, dentist for oral appliances, dietitian, GP for weight pharmacotherapy, ENT for anatomical contributors.
- Expect the comorbidity load — obesity, hypertension, atrial fibrillation, type 2 diabetes, reflux, depression, chronic pain — and build the programme around it.
Clinical reasoning
- Sleepiness, not AHI, is the treatment target for most patients; a modest AHI with severe symptoms deserves more attention than a high AHI with none.2
- Poor response to cardiac or pulmonary rehabilitation with unexplained fatigue should prompt a sleep question before the programme is intensified.
- Distinguish sleepiness (falling asleep) from fatigue (exhaustion without sleep propensity) — the differentials differ, and the second frequently is not OSA.
- Frame every treatment in terms of hours of use or degree of weight change, because both are dose-dependent.1,5
Evidence gaps
- Whether treating OSA reduces cardiovascular events when adherence is high has never been tested in an adequately adherent randomised population.2
- Optimal exercise modality, intensity and duration for reducing OSA severity are undefined.7
- Myofunctional therapy protocols are heterogeneous, small and rarely blinded.8
- Whether incretin-based weight loss can replace positive-pressure therapy, and in whom, is not yet established.6
References for the clinical evidence summary
- Patil SP, Ayappa IA, Caples SM, Kimoff RJ, Patel SR, Harrod CG. Treatment of adult obstructive sleep apnea with positive airway pressure: an American Academy of Sleep Medicine clinical practice guideline. J Clin Sleep Med 2019;15(2):335–343.
- McEvoy RD, Antic NA, Heeley E, et al. CPAP for prevention of cardiovascular events in obstructive sleep apnea (SAVE). N Engl J Med 2016;375(10):919–931.
- Bratton DJ, Gaisl T, Wons AM, Kohler M. CPAP vs mandibular advancement devices and blood pressure in patients with obstructive sleep apnea: a systematic review and meta-analysis. JAMA 2015;314(21):2280–2293.
- Phillips CL, Grunstein RR, Darendeliler MA, et al. Health outcomes of continuous positive airway pressure versus oral appliance treatment for obstructive sleep apnea: a randomized controlled trial. Am J Respir Crit Care Med 2013;187(8):879–887.
- Foster GD, Borradaile KE, Sanders MH, et al. A randomized study on the effect of weight loss on obstructive sleep apnea among obese patients with type 2 diabetes: the Sleep AHEAD study. Arch Intern Med 2009;169(17):1619–1626.
- Malhotra A, Grunstein RR, Fietze I, et al. Tirzepatide for the treatment of obstructive sleep apnea and obesity (SURMOUNT-OSA). N Engl J Med 2024;391(13):1193–1205.
- Iftikhar IH, Kline CE, Youngstedt SD. Effects of exercise training on sleep apnea: a meta-analysis. Lung 2014;192(1):175–184.
- Guimarães KC, Drager LF, Genta PR, Marcondes BF, Lorenzi-Filho G. Effects of oropharyngeal exercises on patients with moderate obstructive sleep apnea syndrome. Am J Respir Crit Care Med 2009;179(10):962–966.
- Strollo PJ Jr, Soose RJ, Maurer JT, et al. Upper-airway stimulation for obstructive sleep apnea (STAR). N Engl J Med 2014;370(2):139–149.
- Chung F, Abdullah HR, Liao P. STOP-Bang questionnaire: a practical approach to screen for obstructive sleep apnea. Chest 2016;149(3):631–638.
Corrections: If something on this page is wrong, out of date or unclear, we want to know. Email reception@inspireclinic.au with the page name and what you believe is incorrect. Substantive corrections are made promptly, and the guide’s version and last-updated date are changed to reflect it.