Sleep Apnea: How to Breathe Freely During Sleep?

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man with sleep apnea snoring

Sleep apnea is a common yet serious condition that usually affects overweight populations. Sleep apneic patients develop difficulty breathing and snore loudly during sleep. Sleep apnea will lead to the hindrance of oxygen supply to the brain, which might result in severe consequences. You are just 10 minutes read away from having a good and healthy sleep by learning more about sleep apnea!


Sleep Apnea Meaning: What is Sleep Apnea?

Sleep apnea is a sleep disorder in which sleep quality is affected. Patients cannot acquire quality sleep as breathing is often interrupted due to multiple factors while asleep. Gaseous exchange cannot be successfully taken, leading to the depletion of oxygen and excessive accumulation of carbon dioxide in the brain. As a result, sleep apnea is detrimental to the mental, physical and social facets of one’s well-being. Sleep apnea can be obstructive or central.

  • Obstructive sleep apnea: The difficulty in breathing is caused by the physical occlusion of the airway.
  • Central sleep apnea: This type of sleep apnea is caused by defects of the central nervous system. Breathing is disorganized because the brain is at fault.
  • Mixed / Complex sleep apnea: Sleep apnea is caused by both physical blockage of the airway and central nervous system failure.
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Causes of Sleep apnea

Sleep apnea is usually caused by organic causes or other underlying conditions. Causes of central sleep apnea and obstructive sleep apnea may not be necessarily related to each other. Common causes of sleep apnea include:


Causes of obstructive sleep apnea:

  • Relaxation of muscle at the back of the throat or aggravating the obstruction of the narrowed airway.

Causes of central sleep apnea:

  • Neuromuscular diseases (such as Lou Gehrig’s Disease)
  • Cardiovascular diseases (such as heart failure)
  • Renal diseases
  • Pulmonary diseases
  • Stroke
  • High altitude periodic breathing
  • Cheyne-Strokes breathing

Risk Factors of Sleep apnea

The aforementioned causes directly lead to sleep apnea. On the other hand, there are several risk factors of sleep apnea that are associated with sleep apnea:

  • Sex: Males are more likely to suffer from sleep apnea.
  • Weight: Being overweight increases the risk of having sleep apnea.
  • Family history of sleep apnea
  • Age: Those above 40 years of age are more likely to have sleep apnea.
  • Size of organs: Regarding neck size, male necks larger than 17 inches are considered dangerous whereas it is 15 inches for females. Also, those with large tonsils, adenoids, tongues and small jaw bones have a higher risk of sleep apnea as well.
  • Anatomical structure of airway (such as receding chin)
  • Sleep posture: Sleeping on your back contributes to a higher chance of obstructive sleep apnea, because the tongue falls back and blocks the airway more directly than sleeping on your lateral side.
  • Nasal obstruction
  • Smoking
  • Alcohol, sedatives or tranquilizers use

Signs and Symptoms of Sleep apnea

Sleep apnea can be easily noticed upon observations of its signs and symptoms even though they vary among patients. Typical signs and symptoms of sleep apnea include:

  • Loud snoring: It is one of the most characteristic signs of sleep apnea, even though not everyone with the disease develops loud snores.
  • Insomnia
  • Bad dreams
  • Dry and sore throat or mouth after sleep
  • Getting woken by a choking or gasping feeling
  • Headache or dizziness after sleep
  • Lack of energy during daytime: Sleep apneic patients may be sleepy and lethargic during daytime. It will be particularly dangerous if they are operating machinery or doing processes that require extra attention.
  • Poor memory or attention span
  • Mood swings or irritability
  • Sexual dysfunction

Complications of Sleep apnea

Untreated sleep apnea may lead to the following complications:

  • Cardiovascular complications: Sleep apnea leads to a lower oxygen level at sleep, hence a higher blood pressure or stronger heart output is required to compensate for the body’s need. Therefore, hypertension, other heart problems and stroke are all possible complications of sleep apnea
  • Metabolic disorders: Sleep apneic patients are more likely to have insulin resistance which may further develop into type 2 diabetes. Thus, blood cholesterol and sugar levels may be out of normal ranges. In addition, liver function may also be impaired in sleep apneic patients, leading to poor metabolism.

Diagnosis of Sleep apnea

Sleep apnea tests are carried out upon the observation of signs and symptoms, diagnosis can be made on the basis of the test results. In patients with history of stroke and/or irregular heartbeat, one should think about sleep apnea as one of the potential underlying causes. The following clinical procedures may also be taken.


Polysomnography: It is more known as a sleep study that monitors multiple things in your sleep, including electrical activity and physical activity. With a sleep study, impaired breathing can be confirmed and the severity of sleep apnea can be established. It can be done at home or at a sleep center. Sleep tests usually involve different procedures like:

  • Electroencephalogram (EEG): Monitor the electrical activity of brain waves.
  • Electromyogram (EMG): Monitor the electrical activity of muscles on the face and limbs.
  • Electrooculogram (EOG): Monitor eye movements.
  • Electrocardiogram (EKG): Monitor cardiac activity.
  • Snore microphone: Monitor snoring.
  • Nasal airflow sensor: Find out if the airflow is smooth.

Oximetry: It is a more convenient, yet less reliable test than polysomnography. A sensor is placed onto the fingertip or earlobe to measure the oxygen saturation at sleep, which finds out if enough oxygen is delivered to the body parts.

Treatments of Sleep apnea

Sleep apnea can be treated with lifestyle modifications that relieve its symptoms and reduce the influences of the risk factors. This includes losing weight if overweight, avoiding alcohol, quitting tobacco or hypnotics, preventing allergens, and altering sleeping postures like avoiding sleeping on your back. 


The following approaches may also be adopted to treat sleep apnea: 

  • Mechanical therapy: Positive airway pressure (PAP) is applied. The principle is to create a pressure difference to keep the airway open by putting a mask over the nose or mouth during sleep. The most common form of PAP is continuous positive airway pressure (CPAP). There are also other PAPs including bi-level PAP and adaptive servo-ventilation (ASV).
  • Mandibular advancement splint: It is a mouthpiece that pushes the lower jaw forward so that the tongue does not block the throat, allowing the maintenance of an opened airway.
  • Neurostimulation: A hypoglossal nerve stimulator is placed into the right chest to stimulate the tongue to move forward and keep the airway open during bedtime.
  • Surgeries: Surgeries can be operated to minimize the obstruction in obstructive sleep apnea. They are often considered in severe cases only. For example, if it is the pharynx that causes obstructive sleep apnea, tonsillectomy may be considered to remove the tonsillar tissues at the back of the throat.
  • Treatment of the underlying factors: This is especially important for treating central sleep apnea. For example, if brain infection is the cause of central sleep apnea, treatment approaches would mainly focus on treating the brain infection along with the complementary relief of sleep apnea like mechanical therapy.


What is considered a serious sleep apnea?

The commonly accepted definition for serious (severe) sleep apnea is defined by apnea-hypopnoea index (AHI). It means how many pauses in breathing occur per hour asleep. Serious (severe) sleep apnea refers to when the patients’ AHIs are higher than 30, while the AHIs values of moderate and mild sleep apnea are 15-30 and 5-15 respectively.

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This article was medically reviewed by Dr. Cheung Yu, Vincent 張宇醫生. Dr. Cheung is a specialist in family medicine practicing at HKSH Medical Group. He is currently an honorary clinical assistant professor in family medicine at HKU and clinical associate professor (Honorary) in family medicine at CUHK.

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This article was independently written by Healthy Matters and is not sponsored. It is informative only and not intended to be a substitute for professional medical advice, diagnosis or treatment. It should not be relied upon for specific medical advice.

Dr. Cheung Yu Vincent
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