What is sleep apnea/sleep disordered breathing?

This is a commonly occurring phenomenon affecting the pharynx which is a muscular tube situated behind the nose and mouth connecting to the windpipe (trachea). This tube varies in configuration and size depending on facial and head structure. There are often features that run-in families.

In wake the tube has muscle tone which means it stays rigid with the negative pressure of inspiration. With sleep this tone gradually falls off leading to tube collapse with each breath in. Depending on the degree of floppiness the tube will partially block or fully block. The person will try and stay asleep until the forces of increased effort of breathing and changes of oxygen and carbon dioxide lead to arousal from sleep. This will repeat itself many times (10-100/hour) during sleep despite the airway instability because the drive to sleep is so strong. However, the quality of sleep is poor because of frequent brief periods of wakefulness (not appreciated by the sleeper) and because of increased work of breathing from the partially and fully blocked airway.

The whole process can be made better or worse by the ease of collapse of the airway, the sleeper’s sensitivity to this process (arousability) and brain controller responses to these breathing changes (loop gain).

Dealing with undiagnosed sleep disorders

Approximately 80% of people with sleep disorders are undiagnosed. Around 1.5 million Australians are thought to have some sleep disorder, of which OSA is the most common. While OSA can present itself in patients with a wide range of histories, some of the recognised risk factors are:

  • Medications: certain medications will aggravate sleep disordered breathing including pain medication and sedatives.
  • Age: patients over 50 years of age may be at a higher risk for developing OSA.
  • Facial structure: some abnormalities, such as a small chin or misaligned bite can have an impact on the chance of developing OSA.
  • Family history: OSA or other breathing/sleep related issues within the family may increase risk.
  • Neck circumference: A neck circumference in excess of 43cm for men and 40cm for women may heighten the chance of a person developing OSA.
  • Diet: excess weight will amplify sleep disordered breathing

Who is at risk?

OSA can manifest itself in people from a very broad range of backgrounds. While age can play a part in increasing the risk factor, OSA can manifest itself in people of all ages and genders. Men are at a higher risk than women, although this levels out post-menopause.

Research indicates that there are a range of correlations between OSA, other health concerns and related issues:

  • A person suffering from OSA is seven times more likely to be in a car accident.
  • Among obese people, 77% suffer from OSA.
  • Nearly 70% of stroke victims also have OSA.
  • Of those suffering from Type 2 Diabetes, 58% have OSA.
  • 83% of people who receive medication for high blood pressure have OSA.

Symptoms of OSA

There are many symptoms and indicators of a person possibly having OSA, and OSA patients vary in their exhibition of symptoms. They will often display at least one of the below:

  • Snoring often but not always loud
  • Obstructive breathing during sleeping, often manifested as choking or gasping
  • Easy sleep when not busied.
  • Behavioural changes, such as irritability, anxiety and in some cases, depression
  • Reduced energy
  • Restless and disrupted sleeping patterns
  • Diminished cognitive abilities, particularly memory and concentration
  • A predilection for napping during the day
  • Sore throat and/or dry mouth in the morning
  • Headaches upon waking

Because many people are unaware that they suffer from OSA, it is possible for some patients to believe they are not experiencing some symptoms, although it will become apparent during a sleep study that they are.

National Statistics on OSA

Reliable statistics on the prevalence of OSA in Australia are difficult to obtain. Occurrence varies widely across demographics, and OSA has only recently received significantly funded studies. Some studies indicate that around one in ten Australians suffer from OSA. A 2016 study found that:

  • 2% of people aged 18-25 are diagnosed with OSA.
  • 8% of people aged 45-55 are diagnosed with OSA.

However, statistical estimates for people who remain undiagnosed present significantly higher numbers. For example:

  • Up to 49% of males aged 40-69 may suffer from OSA.
  • Up to 62% of males older than 70 may suffer from OSA.

Other health conditions

OSA is significantly associated with a range of medical concerns, many of which can cause serious health complications. Patients with OSA typically have poorer physical and mental health, reduced overall wellbeing, concentration and memory.

Some of the other medical concerns that have a statistically significant association with OSA include:

  • Asthma
  • Chronic obstructive pulmonary disease
  • Chronic bronchitis
  • Diabetes
  • Hypercholesterolemia
  • Hypertension
  • Heart attack and heart failure
  • Angina
  • Depression
  • PTSD
  • Anxiety-related disorders
  • Schizophrenia
  • Obesity
  • Gout
  • Insomnia
  • Erectile dysfunction
  • Reduction in cognitive abilities
  • Cardiovascular disease

When you have this condition, during your sleep your breath can become very shallow or you may even stop breathing – briefly. It can happen many times a night in some people, and each of these events are known as apneas (or hypopneas).

Your general practitioner is able to directly refer on the basis of qualifying Sleepiness Scale questionnaire and clinical assessment questionnaire that are available on this website,

Alternatively, a referral to Dr Williams will suffice on most occasions.