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Patients with obstructive sleep apnoea (OSA) have repeated episodes of partial or complete obstruction of the throat (also known as “pharynx” or “upper airway”) during sleep. 

During sleep, a person’s throat muscles relax allowing the tongue and/or fatty tissues of the throat to fall back into the airways and block airflow. During an apnoea event air is restricted from moving beyond the obstruction reducing blood flow to the brain. This in turn signals the brain to partially awaken from sleep to signal the body that it needs to breathe. This is often followed by a loud gasping, choking, or snorting sounds as the person takes a deep enough breath to fight past the obstruction.

Once a breath is taken the brain returns to sleep, and the process begins once again. This process can occur just a few times a night or hundreds of times a night depending on the severity of the condition.

When this occurs several times an hour, it decreases the quality of sleep an individual receives, opening up a whole range of subsequent medical issues. Sleep is a very important part of maintaining good health and without proper sleep a persons overall health can be seriously affected

While many people may be familiar with the most prevalent form of sleep apnoea, obstructive sleep apnoea, it often goes unrecognised that there are two other types of apnoeas that a person can suffer from, Central sleep apnoea and mixed sleep apnoea.

What is Obstructive Sleep Apnoea?

Obstructive Sleep Apnoea (OSA) is the most common form of sleep apnoea and is believed to affect approximately 4% of men and 2% of women. However, it is believed that only about 10% of people with OSA seek treatment leaving the majority of OSA sufferers undiagnosed.


  • Snoring that is loud, disruptive, and regular is one of the most obvious signs of potential OSA.
  • Frequent breaks in breathing caused by an obstruction. These cessations are often followed by choking or gasping noises as the body’s respiratory system fights through the blockage.
  • Excessive drowsiness caused by frequent interruptions of sleep.
  • Morning headaches stem from the loss of oxygen in your bloodstream that flows to your brain as a result of the irregular breathing at night.
  • Restless sleep. Sufferers of obstructive sleep apnoea often have fitful sleep as their mind and body are constantly awakened throughout the night, pulling them out of the much needed stages of non-REM and REM sleep.
  • Depression or irritability. Lack of regular quality sleep can wreak havoc on a person’s mental well-being. Sufferers of obstructive sleep apnoea often find themselves feeling short-tempered, and in time it can lead to more severe symptoms of depression.

Causes and Risk Factors

  • Weight – In many cases a person’s body weight is directly linked to having obstructive sleep apnoea. People who are overweight or obese are more likely to have sleep apnoea than those that maintain a healthy weight. Sleep apnoea can often be caused by excess fatty tissues that become built up in the neck and throat. This can lead to restrictions in airflow as the upper respiratory system’s pathway is narrowed or pinched off during sleep.
  • Age – As people age their muscles begin to lose muscle tone. This is also true of the muscles in the throat. As throat muscles lose definition, they become weaker and more likely to collapse into the airways during sleep.
  • Enlarged tonsils or adenoids are the leading cause of obstructive sleep apnoea in children but can also affect adults who never had a tonsillectomy when they were younger.
  • Natural causes – Some people can be genetically predisposed to having a narrower throat or may have an enlarged tongue that falls back into their airway. If your family has a history of OSA you are more likely to have it yourself.
  • Frequent alcohol use – Alcohol relaxes the muscles in the body, and this includes the throat muscles as well which may relax to the point of blocking the airway during sleep.
  • Smoking – Smoke is an irritant to the lungs, throat, and oesophagus. It can cause inflammation and fluid retention in the upper airways that can impede airflow.


  • Continuous Positive Airway Pressure (CPAP) Therapy (link)
  • Oral Appliances
  • Surgery

For a discussion about the various treatment options call our sleep clinic on 07 4054 2440

What is Central Sleep Apnoea?

Central Sleep Apnoea (CSA) occurs when the brain temporarily fails to signal the muscles responsible for controlling breathing. Unlike obstructive sleep apnoea, which can be thought of as a mechanical problem, central sleep apnoea is more of a communication problem.

Central sleep apnoea is often caused by medical problems and conditions that affect the brainstem. These different causes often lead to varying symptoms and different types of central sleep apnoea.


  • Stopping breathing or irregular breathing during sleep
  • Shortness of breath leading to awakenings
  • Excessive drowsiness
  • Chronic fatigue
  • Morning headaches
  • Poor/restless sleep
  • Difficulty concentrating
  • Mood changes

Causes or conditions that can lead to CSA

  • Parkinson’s disease
  • Medical conditions that affect the brain stem including brain infection and stroke
  • Obesity
  • Certain medications like narcotic painkillers
  • Heart failure

Risk Factors

  • Men are more likely to develop CSA than women
  • More common among older adults, especially those over 65
  • People with heart disorders such as atrial fibrilation and congestive heart failure are at greater risk
  • Those who have had a stroke or have a brain tumour
  • If you use opioid medications are at greater risk
  • Some people with obstructive sleep apnoea can develop central sleep apnoea when they’re being treated with positive airway pressure (PAP) devices.


  • Treating existing conditions that are causing CSA is often the first line in treatment options for the disorder.
  • Continuous Positive Airway Pressure (CPAP).  A CPAP device includes a breathing mask that sleep apnoea sufferers wear when sleeping. Just enough consistent air pressure is delivered via the mask to the patient’s airways to keep the tissue that otherwise would collapse (and cause breathing pauses and snoring) from closing during sleep. CPAP devices are effective in treating sleep apnoea but do not cure the disorder. If you discontinue using your CPAP device, your sleep apnoea may return.
  • Medications. Certain medications, such as acetazolamide (Diamox) or theophylline (Theo-24, Theochron, others), have been used to stimulate breathing in people with central sleep apnoea. Medications may be prescribed when positive airway pressure therapy fails to be efficient.

What is Mixed Sleep Apnoea?

Mixed sleep apnoea is a combination of both obstructive and central sleep apnoea symptoms. Some patients being treated for obstructive sleep apnoea with the use of CPAP machines develop symptoms of central sleep apnoea upon PAP therapy.


Optimal treatment options for mixed sleep apnoea still need to be refined. Currently one of the best treatments is still CPAP devices, but set at the lowest possible pressure setting that successfully keep the airways free from obstructions, but don’t allow CSA symptoms to develop.

What to do next

If you live in North Queensland believe that you may have symptoms of sleep apnoea, click the link below to schedule a free phone consultation with one of our clinical sleep specialists. In just 10 minutes we can help you discover whether or not your symptoms warrant a sleep study to help you get diagnosed and treated for your sleep disorder.


DISCLAIMER: This information is an educational aid only. It is not intended to replace medical advice for individual conditions or treatments. Talk to your doctor, pharmacist, nurse or naturopath before following any medical regimen to see whether it is safe and effective for you.