Types of sleep apnoea
There are two types of sleep apnoea: obstructive sleep apnoea and central sleep apnoea.
Obstructive sleep apnoea
The most common type of sleep apnoea, obstructive sleep apnoea (OSA), happens when airways are obstructed during sleep, for instance by the tongue.
OSA is often undiagnosed, leaving the sufferer tired, irritable and possibly vulnerable to health problems such as high blood pressure, diabetes and coronary disease – all without knowing the reason why, other than perhaps an awareness of not sleeping that well. Other major problems, such as falling asleep at the wheel, can also result from leaving OSA unchecked. If you find it hard to stay awake during the day (especially in the afternoon), wake up feeling tired despite the amount of sleep you've had, or fall asleep easily in the afternoon, have yourself assessed for OSA.
Central sleep apnoea
Central sleep apnoea (CSA) is a far less common condition than OSA. Respiration at night is affected by a disorder in brain function. Its symptoms and diagnosis are similar to OSA, but treatment is more complicated.
Causes of sleep apnoea
Sleep apnoea can be brought about or hastened by factors such as:
- obesity or weight gain
- sedative use
- anatomical reasons, including enlarged tonsils.
Symptoms of sleep apnoea
There are several symptoms of sleep apnoea, which range in severity. They include:
- snoring, especially if accompanied by pauses, snorts, and gasps for air
- waking feeling unrefreshed
- daytime sleepiness
- mood swings.
Diagnosis of sleep apnoea
Sleep apnoea is generally diagnosed in a sleep lab using a polysomnogram a test measuring various physiological activities while you sleep.
There are a number of treatments available for sleep apnoea.
Sometimes weight loss, not sleeping on your back, and avoiding alcohol and sedatives are enough to manage OSA.
Continuous positive airway pressure (CPAP) is thought to be the most effective non-invasive treatment for obstructive sleep apnoea, and is sometimes helpful to treat CSA. The CPAP machine has a nasal mask that blows air through the nose and holds the airway open, helping you breathe regularly through the night.
Sufferers of CSA may find relief with a BiPAP (bi-level positive airway pressure) device, similar to CPAP but with timed bursts for inhalation and exhalation, or supplemental oxygen.
In some cases, surgery may be suggested to treat sleep apnoea. For children with obstructive sleep apnoea, this often involves taking out their tonsils and adenoids.
Occasionally, adults may also undergo surgical procedures for the condition. Surgery can be helpful, but only if it's performed on the appropriate people, such as those who aren't overweight but have a large palate that's causing obstruction. For CSA, surgery might involve inserting a diaphragm pacemaker.
Sleep apnoea may also be treated with mandibular splints – dental appliances that can move the jaw forward or stop the tongue falling backwards. Experts say the newer appliances are more comfortable than the bulky mouthguards of old, and are good for people with apnoea who can't tolerate the CPAP machine. Mandibular splints must be prescribed by a sleep medicine or ENT specialist, who'll then refer you to a dentist and dental technician to make and fit the device.
Studies suggest medication is an ineffective treatment for OSA, but respiratory stimulant medication can help CSA.