Sleep apnoea

If you have sleep apnoea, the walls of your throat come together while you sleep, blocking off your upper airway. You stop breathing for a period of time (generally between ten seconds and up to one minute) until your brain registers the lack of breathing, or a drop in oxygen levels, and sends a small wake-up call. This causes you to rouse slightly, open your upper airway, possibly snort and gasp, and then drift back to sleep almost immediately. In most cases, you won’t even realise you are waking up. 

This pattern can repeat itself hundreds of times every night, causing you to have fragmented sleep. This can leave you feeling unrefreshed in the morning, with excessive daytime sleepiness, poor daytime concentration and work performance, and fatigue. 

It’s estimated that about five per cent of Australians suffer from sleep apnoea, with around one in four men over the age of 30 years affected. 

Degrees of severity of sleep apnoea

The full name for this condition is obstructive sleep apnoea. Another rare form of breathing disturbance during sleep is called central sleep apnoea. It is caused by a disruption to the mechanisms that control the rate and depth of breathing. The severity of sleep apnoea depends on how often the breathing is interrupted. As a guide:

• normal sleep – fewer than five interruptions per hour
• mild sleep apnoea – between 5 and 15 interruptions per hour
• moderate sleep apnoea – between 15 and 30 interruptions per hour
• severe sleep apnoea – more than 30 interruptions per hour.

Symptoms of sleep apnoea

People with significant sleep apnoea have an increased risk of motor vehicle accidents and high blood pressure, and may have an increased risk of heart attack and stroke. In the over-30 age group, the disorder is about three times more common in men than women. Some of the associated symptoms include:

• daytime sleepiness, fatigue and tiredness
• poor concentration
• irritability and mood changes
• impotence and reduced sex drive
• need to get up to toilet frequently at night.

Causes of sleep apnoea

Obesity is one of the most common causes of sleep apnoea. Other contributing factors include:

• alcohol, especially in the evening – this relaxes the throat muscles and hampers the brain’s reaction to sleep disordered breathing
• certain illnesses, such as reduced thyroid production or the presence of a very large goitre
• large tonsils, especially in children
• medications, such as sleeping tablets and sedatives
• nasal congestion and obstruction
• facial bone shape and the size of muscles, such as an undershot jaw.

Treatment for sleep apnoea

The first line of treatment for sleep apnoea is making changes to your lifestyle, including losing weight and cutting down on alcohol. 

If you have any contributing medical conditions, such as low production of thyroid hormone or large tonsils, these also need to be corrected. 

In addition to lifestyle changes, the most effective treatment available is a mask worn at night that prevents the throat from collapsing by transmitting increased air pressure to the collapsible segment of the throat. This is called ‘nasal continuous positive airway pressure’ (CPAP). The key to this treatment is finding a mask and machine that match your needs.

If you have mild to moderate sleep apnoea, another possible treatment is the use of a specially made mouthguard (or oral appliance or mandibular advancement splint). Mouthguards work by holding your jaw forward during sleep. 

Although not always effective, surgery to the palate and base of tongue may be useful when other therapies fail. These types of surgeries are best undertaken by otolaryngologists (ear, nose and throat surgeons) who take a special interest and have had training in sleep-related surgery.

Where to get help

• Your GP (doctor)
• Sleep disorders clinic
• Australasian Sleep Association Sleep Services Directory