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Snoring and Obstructive Sleep Apnea (OSA)

What are Snoring and Obstructive Sleep Apnoea (OSA)?


Snoring refers to noisy breathing during sleep. It is due to the vibration of the soft palate, uvula, base of tongue and other soft tissues in the throat when one breathes. Snoring occurs when the upper airway narrows during breathing, causing an increased resistance to air flow.
Snoring may be a sign of a potential serious medical problem when you experience daytime sleepiness and choking sensation at night. This condition is known as Obstructive Sleep Apnoea.

Obstructive Sleep Apnoea (OSA)

OSA is a sleep disorder characterised by repetitive blockage (obstruction) of the upper airway, causing pauses in breathing (apnoeas) during sleep. OSA often causes a drop in blood oxygen level. This leads to recurrent awakening at night to re-establish breathing.
Based on a local population screening, 31% of Singaporean adults have OSA but majority were previously undiagnosed.

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Complications of untreated OSA include:

  • High blood pressure

  • Irregular heart beat

  • Heart attack

  • Stroke

  • Diabetes mellitus



  • Excessive sleepiness

  • Poor concentration

  • Dry mouth and throat when waking up


  • Excessive snoring

  • Choking episodes

  • Frequent awakening

  • Observed by bed partner to 'stop breathing'


Diagnosis of OSA requires:

  • Detailed clinical assessment

  • Flexible nasoendoscopy – this is a procedure where a thin flexible camera is passed through your nose and throat for examination

  • Overnight sleep study

The severity of OSA is measured in terms of the number of episodes of reduction in airflow (hypopnoeas) or lack of airflow (apnoeas) per hour over a night's sleep, known as Apnoea-Hypopnoea Index (AHI):

  • Normal: Less than 5

  • Mild OSA: 5-15

  • Moderate OSA: 15-30

  • Severe OSA: 30 or more

How are Snoring and Obstructive Sleep Apnoea (OSA) treated?

1. Lifestyle Modifications and Weight Management

A healthy lifestyle and good sleep hygiene are recommended for all. Weight management is recommended for those who are overweight.

2. Positive Airway Pressure (PAP) Therapy

This is a non-invasive treatment that involves the use of a face mask to maintain positive airway pressure. The face mask is worn by the patient throughout the night. PAP is the most effective treatment for OSA. However, not everyone can tolerate long term use.

3. Oral Appliance

A mouthpiece that is worn while sleeping to prevent the airway from collapsing. It works by repositioning the tongue or jaw forward.

4. Positional Therapy

This uses techniques to avoid sleep in the supine (on the back) position. This form of therapy may be effective for some OSA patients.

5. Upper Airway Surgery

This is an alternative treatment for OSA. Surgery is an option for:

  • Patients whose narrow upper airways can be corrected through surgery

  • Those who cannot tolerate Positive Airway Pressure (PAP) therapy

Surgical treatment has shown to be effective in certain groups of patients.

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