Quick answer. Obstructive sleep apnoea (OSA) is a common condition in which the upper airway repeatedly collapses during sleep, briefly stopping breathing and dropping oxygen levels. Singapore studies suggest around 1 in 3 adults have moderate-to-severe OSA, and most cases are undiagnosed. Typical signs are loud snoring, witnessed breathing pauses and excessive daytime sleepiness. Diagnosis is made with a sleep study, either an in-lab polysomnography or a home sleep test, which measures the Apnoea-Hypopnoea Index (AHI) to grade severity. Untreated OSA raises the risk of high blood pressure, heart disease, stroke, atrial fibrillation, diabetes and road accidents. CPAP (continuous positive airway pressure) is the gold-standard treatment for moderate-to-severe OSA. This guide focuses on the sleep-study and CPAP pathway and is general information, not medical advice.
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Obstructive sleep apnoea (OSA) is a sleep-related breathing disorder in which the muscles of the upper airway relax and collapse during sleep, repeatedly interrupting breathing and lowering blood oxygen. It is strikingly common in Singapore: local research suggests around one in three adults has moderate-to-severe OSA, and the great majority remain undiagnosed. Left untreated, OSA is linked to serious heart, brain and metabolic problems, as well as dangerous daytime sleepiness. This guide focuses on the respiratory and sleep-medicine pathway, how OSA is diagnosed with a sleep study and how CPAP therapy works. Surgical options for snoring are covered in our separate ENT guide. This is general information only and not a substitute for advice from your own doctor.
At a glance
| Severity | AHI (events per hour) | General significance |
|---|---|---|
| Normal | Fewer than 5 | No significant sleep apnoea |
| Mild | 5 to 15 | May warrant treatment if symptomatic |
| Moderate | 15 to 30 | Treatment commonly recommended |
| Severe | More than 30 | Treatment strongly recommended, often CPAP |
What is OSA and what are the symptoms?
In OSA, the soft tissues of the throat relax during sleep and block the airway, causing repeated pauses in breathing (apnoeas) and partial reductions (hypopnoeas), each followed by a brief arousal and a dip in oxygen. The hallmark symptoms are loud, habitual snoring, witnessed breathing pauses or gasping and choking awakenings, and excessive daytime sleepiness, the most common complaint. Other features include unrefreshing sleep, morning headaches, dry mouth, poor concentration, mood changes and waking to pass urine. A simple questionnaire called the Epworth Sleepiness Scale is often used to gauge daytime sleepiness. OSA is notably common in Singapore, including among those who are not significantly overweight.
The diagnosis pathway and sleep studies
If OSA is suspected, you will usually be referred to a respiratory or sleep physician, who will arrange a sleep study to confirm the diagnosis. An in-lab polysomnography (PSG) is the diagnostic standard: an overnight, non-invasive test in a sleep laboratory that records sleep stages, breathing effort, airflow, oxygen levels, heart rhythm and muscle activity. A home sleep test is a more convenient and less costly alternative that is reasonably accurate for people with a high likelihood of moderate-to-severe OSA, though it captures less detail. The results are summarised as the Apnoea-Hypopnoea Index (AHI), the average number of breathing events per hour, which grades severity as mild, moderate or severe.
Why untreated OSA matters
OSA is not just about snoring or feeling tired. The repeated drops in oxygen and disrupted sleep place strain on the heart and blood vessels. Untreated OSA is strongly associated with high blood pressure, heart disease and heart failure, stroke, irregular heart rhythms such as atrial fibrillation, and type 2 diabetes. The excessive daytime sleepiness it causes also markedly increases the risk of motor vehicle accidents. Singapore heart and sleep centres highlight that a large share of people with hypertension or who have had a stroke also have OSA, which is why diagnosing and treating it is important for overall health.
CPAP therapy explained
Continuous positive airway pressure (CPAP) is the gold-standard treatment for moderate-to-severe OSA. A small bedside machine delivers a gentle, steady stream of pressurised air through a tube and mask worn during sleep, which splints the airway open and prevents it from collapsing. Many users feel more alert and sleep better within days to a few weeks. The main challenge is getting used to the mask, so an adjustment period and proper pressure setting (titration) are important; auto-adjusting machines (APAP) vary the pressure automatically and can track usage data. Sticking with CPAP is worthwhile, as consistent use delivers the health benefits.
Alternatives to CPAP
CPAP is the mainstay for moderate-to-severe OSA, but other measures play a role, particularly in milder cases or alongside CPAP. Weight loss can significantly reduce OSA severity. Positional therapy (avoiding sleeping on the back) and reducing alcohol, especially before bed, can help. For mild-to-moderate OSA, a custom mandibular advancement device (an oral appliance that holds the lower jaw forward) is an option. Surgery to the upper airway is sometimes considered and is covered in our separate ENT guide on snoring and sleep apnoea. Your sleep physician can advise which combination suits you.
Costs and when to see a sleep physician
As a guide only, an in-lab polysomnography in the private sector commonly ranges from about S$800 to S$1,500, while a home sleep test is typically around S$300 to S$500; public and subsidised settings differ, and MOH publishes bill benchmarks for sleep apnoea procedures. A CPAP machine is usually a personal purchase, commonly ranging from about S$800 to S$2,500 depending on features, plus masks and consumables; rental options exist. Sleep studies may be claimable under some insurance plans, and MediSave use depends on the specific procedure, so check with your provider. See a respiratory or sleep physician if you have loud snoring with witnessed pauses, choking or gasping in sleep, or persistent daytime sleepiness despite adequate sleep. Confirm current fees with the clinic.
Related guides
- Best Respiratory & Lung Clinics in Singapore — our editorial shortlist
- Asthma care
- COPD care
- Chronic cough
Sources
- HealthHub (MOH) – Obstructive Sleep Apnoea
- SingHealth Duke-NUS Sleep Centre – All About OSA
- SingHealth – OSA Conditions and Treatments
- NUHCS – Obstructive Sleep Apnoea
- MOH – Sleep Apnoea Bill Benchmark (DRG E63Z)
Related conditions & guides
Related conditions and guides you may find useful:
- Insomnia Treatment in Singapore
- Narcolepsy in Singapore
- Restless Legs Syndrome (RLS) in Singapore
- Shift Work & Jet Lag Sleep Problems in Singapore
- Sleep Study (Polysomnography) in Singapore
- Snoring & Obstructive Sleep Apnoea (OSA) Treatment in Singapore
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