Doctor On Call (DOC): Dr Valerie Tay – Why Snoring Is Bad For Your Health (Part 1)

Doctor On Call, or DOC for short, is a brand new series brought to you by Medical Channel Asia. This series aims to bring doctors and specialists from various fields to give you an introduction to common health and medical topics that you and the Asian population are interested in. In our 10th DOC, held on 18 Mar 2022 (Wednesday) in line with World Sleep Day, from 8 pm to 9 pm (GMT+8), we have Dr Valerie Tay, Senior consultant Ear, Nose and Throat surgeon, ASCENT ENT Specialist Group, to talk to us about Obstructive Sleep Apnea (OSA). Read on to learn more about OSA and snoring.

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For Part 1 of the forum, we have Dr Valerie Tay give us a presentation on airway anatomy, risk factors and complications of OSA as well as treatment options in both adults and children.

In Part 2, Dr Valerie Tay goes through many questions posted by our enthusiastic audience, both collated from the registration process, and also posted LIVE. Read below to find out more about sleep apnea.

Presentation by Dr Valerie Tay

Introduction & Epidemiology

In a study done, published in 2006, almost 50% of adults in Singapore snore; and 26.1% felt that it would affect their marital life. Another study had shown that 1/3 of adults in Singapore have moderate to severe OSA, and it is almost twice as likely in men than women.

Children, 1-3% of them have OSA, and the consequences can be quite severe.

Snoring vs OSA

Airway anatomy

The nose is divided into the left and right sides, by a wall (nasal septum). There are soft tissues at the side walls of the nose, known as the inferior turbinates. Nasal obstruction can be caused by a deviated nasal septum or enlarged inferior turbinates. Nasal obstruction can lead to mouth breathing, which then contributes to snoring and even OSA.

When we look into our mouth, some of us may be able to see the uvula (a hanging part of the palate) and the tonsils. The roof of the mouth (hard palate) continues into the muscular soft palate.

At the back of the nose, there is a possibility of the development of soft tissue called adenoids. This happens especially in children, and they may be enlarged due to allergies. The enlargement of adenoids can also cause nasal obstruction.

Why do we snore?

When we breathe, air travels through the nose, down the back of the throat, and through the windpipe to reach the lungs. When we are awake, the muscles keep the airway open such that the air can flow smoothly. When we are asleep because the muscle loses tone, the back of the tongue and the palate can flop back, causing partial obstruction, and airway turbulence and resulting in vibration of the palate, which causes snoring.

What happens in OSA, is that there is a complete obstruction of the airway, such that the oxygen cannot reach the lungs (and carbon dioxide cannot come out as well). When the carbon dioxide builds up in the bloodstream, the brain is triggered to wake up so that breathing can occur again.

Definitions: Snoring and Obstructive Sleep Apnea (OSA)

Snoring: A sound produced by the vibration of airway muscles, usually the soft palate.

Obstructive sleep apnea (OSA): Recurrent ‘blockage’ of the upper airway during sleep, leading to reduced airflow to the lungs and sleep disruption. OSA is associated with many heart problems and medical conditions.

Sleep study

The first sleep lab was established in the 1960s in America. Sleep studies performed in sleep labs are to measure brain waves, oxygenation, heart rate, and movements of the body during sleep.

Sleep studies can also be done at home, but it would be simpler with fewer electrodes over the head and the body compared to one done in the sleep lab.

The sleep study will indicate whether or not there is OSA and its severity.

The severity of OSA is determined by the Apnoea-Hypopnoea Index (AHI) measures OSA severity. The AHI is the sum of the number of apnoeas (pauses in breathing) plus the number of hypopnoeas (periods of shallow breathing) that occur, on average, each hour.

OSA severity

Adults Children


<5 0-1
Mild 5-15





Severe >30


The number of AHI can then determine the severity of OSA, as classified in the table above.

OSA in adults

Risk factors

Risk factors for sleep apnea include:

  • Male
  • Obesity
  • Smoking
  • Menopause
  • Increasing age


Symptoms of OSA may include:

  • Daytime sleepiness
  • Morning headaches
  • Dry mouth
  • Choking & gasping
  • Going to pass urine at night
  • Abrupt awakenings


The consequences of OSA have been highlighted more in recent times by the media.

Some of the consequences of OSA include:

  • Heart attacks
  • High blood pressure
  • Traffic accidents (up to 10 fold increase)
  • Stroke
  • Diabetes


  • Continuous positive airway pressure (CPAP) machine

The use of a CPAP machine is the gold standard of treatment for OSA, for patients who can tolerate the treatment. CPAP pumps in pressure through tubing into a mask, which forces the higher pressure into the nose and the airway so that it is kept open at night.

The issue with CPAP is that it may not be very comfortable and patients may need some time to get used to the machine. Some complaints include the mask slipping off, and dryness (of the airways).

  • Weight loss

As obesity is one of the risk factors for OSA, weight loss is an important part of the treatment plan.

  • Surgery

Surgery is an option for those who cannot tolerate CPAP. Surgery is typically multilevel: the surgeon may operate on the nose, palate, and tongue.

Obstructive Sleep Apnea in children

Risk factors

Risk factors for OSA in children include:

  • Obesity
  • Genetics
  • Prematurity
  • Exposure to secondhand smoke


Symptoms of OSA in children can be different from those in adults, and may include:

  • Increased napping
  • Mouth breathing
  • Poor appetite
  • Choking & gasping
  • Poor concentration in school
  • Hyperactivity


  • Facial deformities

Chronic mouth breathing and snoring in children is typically due to enlarged tonsils and adenoids. The child may have a typical appearance of a hanging jaw, a long face, and allergic shiners.

This happens as the hard palate must undergo widening during development. This sideways force is exerted by the presence of the muscular tongue up against the hard palate. The problem with a chronic mouth breather is that the mouth is constantly open, and this change in jaw and tongue position leads to a narrow palate and crowding of teeth, and a small jaw.

Other consequences of OSA in children include:

  • High blood pressure
  • Irregular heart rhythm
  • Metabolic syndrome
  • ADHD
  • Poor academic grades


  • Early removal of tonsils and adenoids (adenotonsillectomy), or “watch and wait”?

Studies show that for the children who had early adenotonsillectomy, there were greater improvements in symptoms and quality of life when compared to those who did not undergo the procedure.

Sleep study findings were also normalized in a larger proportion of the children who received early adenotonsillectomy, versus those who did not undergo the procedure (79% vs 46%).


Adult OSA, if left untreated, can cause many complications such as high blood pressure, heart problems, stroke, diabetes, and even an increase in traffic accidents. Treatment of adult OSA is often with the use of a CPAP machine, weight loss, and surgery for certain anatomical problems.

In childhood and adolescence OSA, if left untreated, can cause facial deformities, heart problems, metabolic syndrome, behavioural problems, and lower academic grades. Childhood OSA is most commonly related to obesity and enlarged tonsils and adenoids. In the presence of such enlarged tonsils and adenoids, early removal is important to prevent complications from arising.

What’s next in store?

  • See Part 2 for the Question and Answer (Q&A) segment with Dr Valerie Tay!
  • If you have missed our previous DOC webinars, visit our Medical Channel Asia’s YouTube page, or you can also read the articles:
    • Doctor On Call (DOC): Dr Sean Leo – Common Sports Injuries Part 1Part 2
    • Doctor On Call (DOC): Dr Lee Fang Jann – Men’s Health Part 1Part 2
    • Doctor On Call (DOC): Dr Felix Li – Medical Aesthetics Part 1Part 2
    • Doctor On Call (DOC): Dr Michael MacDonald – The Silent Killer Part 1Part 2
    • Doctor On Call (DOC): Dr Jade Kua – DARE to Save a Heart Part 1Part 2
    • Doctor On Call (DOC): Dr Radhika Lakshmanan – Facts and Myths of Breast Cancer Part 1Part 2
    • Doctor On Call (DOC): Dr Julian Tan – Ischemic Heart Disease Part 1Part 2
    • Doctor On Call (DOC): Dr Leong Hoe Nam – Long COVID Part 1Part 2
    • Doctor On Call (DOC): Dr Eugene Yeo & Dr Toh Ee-Lin – Colorectal Cancer Part 1Part 2

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