Dr KH Lim ENT Clinic

Sleep Apnea

What is Sleep Apnea?

Sleep apnea is a condition where cessation airflow occurs during sleep, meaning you stop breathing while you are sleeping. Sleep apnea may occur due to an obstructive, central or complex ( ie both obstructive and central).  Obstructive sleep apnea is the more common type of sleep apnea.

Obstructive Sleep Apnea (OSA)

Obstructive sleep apnea occurs when there is an obstruction of the upper airway during sleep, blocking it and causing a cessation of the airflow. The common causes of obstruction are large tonsils and adenoid, swollen nasal tissue and deviated nasal septum.  Obesity is an important cause.  Laxed throat or palatal tissues and a bulky tongue can also causes obstructive sleep apnoea.

Central Sleep Apnea (CSA)

Central sleep apnea occurs when the brain fails to send proper signal to the muscles that control breathing, leading to  cessation of the airflow.  In other words, there is a lack of respiratory drive from the brain.  The causes vary from heart failure, stroke, brain injury to chemical or metabolic causes such as narcotic use.  It may occur due to an underlying medical condition too.

Complex sleep apnea syndrome (CSAS)

Complex sleep apnea, also known as treatment-emergent central sleep apnea, is a sleep disorder that involves both obstructive sleep apnea (OSA) and central sleep apnea (CSA) patterns. It is a relatively uncommon condition where a person’s breathing is repeatedly interrupted during sleep due to a combination of factors.

What Causes OSA?

Several factors contribute to the development of obstructive sleep apnea.

obstructive sleep apnea treatment
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Can Sleep Apnea Kill You?

Untreated sleep apnea can lead to serious health complications, and in rare cases, it can be life-threatening. Sleep apnea is associated with an increased risk of high blood pressure, heart disease, stroke, and diabetes. These conditions can increase the risk of premature death.


In severe cases, sleep apnea can cause a person to stop breathing for extended periods, leading to oxygen deprivation, which can result in sudden death. Fortunately, this is a rare occurrence.

Sleep Apnea Symptoms

Sleep apnea symptoms may vary between individuals.  Some of the common symptoms are:

Loud snoring that can be disruptive to both the person and their partners.

A person with sleep apnea my wake up feeling out of breath, gasping and choking, feeling suffocating during their sleep.

Breathing may stop completely due to complete blockage of the airway during sleep.  This may last for several seconds to minutes.

A person with OSA may wake up frequently during sleep most nights.

Nocturia refers to waking up frequently in the night to urinate.

This is postulated to be due to oxygen deprivation during sleep.

Person with sleep apnoea may have difficulty contracting, memory problems or difficulty with decision-making.

Sleep is unrestful due to airway obstruction and oxygen deprivation. This resulted in feelings of tiredness and fatigue, which interfere with work, school and daily activities.

Sleep apnea can cause irritability, mood changes, and even depression due to the disruption of normal sleep patterns.

Sleep Apnea Test & Diagnosis

To diagnose sleep apnea, it typically begins by taking a detailed medical history and performing a physical exam. A sleep study to confirm the diagnosis and assess the severity of the condition is usually recommended. Here are some of the tests and diagnostic methods commonly used to diagnose sleep apnea:

  • Polysomnography (PSG): This is the most common test used to diagnose sleep apnea. It involves spending a night at a sleep centre or hospital, where various sensors are attached to the body to monitor brain activity, eye movement, heart rate, breathing, and other bodily functions during sleep.


  • Home sleep test: This is a simpler version of the PSG that can be performed at home using a portable monitor. The monitor records breathing patterns, oxygen levels, heart rate, and other data during sleep.


  • Physical exam: An ENT specialist may perform a physical exam to look for physical signs of sleep apnea, such as enlarged tonsils, a narrow airway, or a deviated nasal septum.


  • Epworth Sleepiness Scale: This is a questionnaire that measures a person’s level of daytime sleepiness and can help assess the severity of sleep apnea.


  • Oximetry: This test measures the level of oxygen in the blood and can be used to detect oxygen desaturation during sleep.

Once diagnosed, the severity of sleep apnea can be assessed using the apnea-hypopnea index (AHI), which measures the number of apnea and hypopnea events per hour of sleep. Apnoea refers to complete cessation of airflow.  Hyponoea refers to reduced airflow due to obstruction leading to drop in oxygen level and respiratory distress.

Can Sleep Apnea Be Cured?

To cure sleep apnoea is difficult.  Nevertheless, the symptoms of sleep apnoea can be effectively managed to reduce the loudness of snoring and reduce its associated health risk.


Some define success in treatment of sleep apnoea when the apnoea and hypopnoea index (AHI) is reduced by 50% with a residual AHI of less than 10 events/hr.  Based on these criteria, some people with mild or moderate sleep apnoea may be cured. It is harder to ‘cure’ someone with severe sleep apnoea.

Obstructive Sleep Apnea Treatment

The treatment aim of any OSA therapy is to control the symptoms and minimize its long-term morbidity by reducing the frequency of apneas and hypopneas.  The treatments options are:

Lifestyle changes such as losing weight, avoiding alcohol and sedatives, and sleeping on your side instead of your back can also help reduce symptoms of sleep apnea.  Weight loss is paramount in the treatment of sleep apnoea secondary to obesity. It is important to control the weight for long term control of sleep apnoea.

This is the most common and effective treatment for sleep apnea. It involves wearing a mask over the nose or mouth during sleep, which delivers a continuous stream of air pressure to keep the airway open.

Nasal allergy tends to cause nasal obstruction which contributes to upper airway obstruction and mouth breathing.  Mouth breathing causes the tongue base to flop backwards and worsens the airway.  Hence, it is important to control any allergy and clear the nasal obstruction.

These are custom-made devices that fit in the mouth like a mouthguard or orthodontic retainer. They work by repositioning the tongue and jaw to keep the airway open during sleep.

In some cases, surgery may be necessary to treat sleep apnea. The goal of surgery is to remove excess tissue from the throat or reposition the jaw to open up the airway.  Surgery may augment the use of CPAP.  Surgery is usually considered after a failed CPAP trial. As the upper airway is a long structure, surgery is usually multi-level and staged. Some of the common surgeries are

This is postulated to be due to oxygen deprivation during sleep.

It is important to seek medical attention if you experience any of these symptoms, as sleep apnea can have serious health consequences if left untreated.

Why Consult Our ENT Doctor?

Sleep disorder is a complex medical condition.  The treatment ranges from lifestyle, non surgical techniques and surgery.  You need a sleep doctor who is experienced and able to give a holistic and honest approach to treat the problem.  The treatment of sleep disorder is individualised and customised according to the patient’s expectation, anatomy and severity of the sleep disorder.

Sinus Doctor in Singapore - Dr Lim Keng Hua

Our practice built upon mutual trust, sincerity and integrity will provide every patient with a holistic and honest approach to solving sleep problems.


Our doctor, Dr Lim, is an experienced ENT specialist who believes in providing a realistic approach to the treatment of sleep apnoea. Each treatment is individualised according to individual anatomy, severity and expectation.


A holistic approach to treating sleep apnoea will be crafted for each individual. All possible options will be discussed.


The pros and cons of each option, together with its limitations will be displayed. A recommended approach is given only through a thorough discussion with the patient.


Sleep apnea can have serious health consequences if left untreated. It can cause fatigue, memory problems, difficulty concentrating, mood changes such as irritability or depression, morning and nighttime headaches, heart disease and stroke, high blood pressure, and other issues. 

Additionally, it is linked to an increased risk of car accidents due to drowsy driving. Therefore it is important to speak with a doctor if you are experiencing any of the symptoms mentioned above.

Yes, there are several lifestyle changes that can reduce the risk of developing sleep apnea. These include avoiding smoking and alcohol use, limiting exposure to allergens and irritants, reducing contact with individuals who have colds or other infections, practicing good hygiene by washing hands regularly, eating a balanced diet with plenty of fruits and vegetables, drinking plenty of fluids to stay hydrated, getting enough rest and exercise each day. 

Additionally, maintaining a healthy weight can also help reduce the risk of sleep apnea.

Not necessarily. Snoring can be a symptom of sleep apnea, but it is not always the case. Some people who snore do not have sleep apnea and some people who have sleep apnea do not snore. It is important to talk to your doctor if you are concerned that you may have sleep apnea, as other symptoms such as pauses in breathing during sleep or excessive daytime fatigue should also be considered when making a diagnosis. Your doctor may recommend a medical evaluation or overnight sleep study for an accurate diagnosis.

No, sleep apnea is not necessarily caused by stress. While stress can be a contributing factor to the worsening of sleep apnea symptoms, it is not typically a direct cause.

Sleep apnea is usually due to  an obstruction within the airway due to enlarged or blocked tissues such as the tonsils or tongue that prevent regular breathing during sleep. Causes may also include obesity and chronic nasal congestion.

Sleep apnea can affect people of all ages. However it is more common in middle-aged adults and seniors. Children can also be affected by sleep apnea if they have enlarged tonsils or have a family history of the condition. It is important to talk to your doctor if you suspect that you or your child may have sleep apnea, as early diagnosis and treatment are key for successful management of the condition.

The best sleep positions for people with sleep apnea are usually on their side. Sleeping in a prone (on your stomach) position can worsen snoring and obstructive sleep apnea, so it is not recommended. Back sleeping can also increase the risk of snoring and sleep apnea, as gravity can cause the tongue to collapse back into the throat. For optimal airflow, consider using special pillows designed specifically for people with sleep apnea that help support good posture throughout the night while alleviating pressure points.

While snoring is caused by the vibration of tissues in the upper airway, sleep apnea is caused by a complete or near complete blockage or obstruction of the airway. 

Additionally, snoring does not typically lead to any serious health problems but sleep apnea can have serious consequences if left untreated. 

Lastly, snoring occurs during shorter periods of time compared to an episode of sleep apnea, where breathing pauses and becomes shallow for extended periods which interrupts normal sleep patterns.

The only way to determine whether you have sleep apnea or simply snoring is to get a medical evaluation. Your doctor may suggest an overnight sleep study to measure your airway patency and  oxygen levels during sleep, which will help determine the severity of your condition and provide insight into the underlying causes of your breathing difficulties. 

Other signs and symptoms such as excessive daytime fatigue, difficulty concentrating, morning headaches, or choking and gasping episodes during sleep  can also indicate that you have a more serious issue than just snoring. Talk to your doctor if you are concerned that you might have sleep apnea for accurate diagnosis and appropriate treatment options.

Have a question? Call us today

When it comes to sleep apnea or snoring, our ENT specialist clinic is your best choice for a quick and effective obstructive sleep apnea treatment. We provide accurate diagnoses and offer comprehensive treatment tailored to each individual’s needs. Utilizing the latest equipment and technologies, we are able to identify the root cause of your sleep apnea condition and provide a solution that is right for you.

Don’t wait any longer to get the help you need – contact us today! We look forward to helping you on your journey toward recovery.

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