Sleep apnoea is a medical disorder of varying clinical severity, which results from an involuntary cessation of breathing for a short time during sleep. Usually, this is a consequence of the muscles of the throat being completely relaxed and ‘obstructing’ or blocking the airway. This disorder is commonly referred to as obstructive sleep apnoea (OSA).
Sleep apnoea symptoms are often worse when lying on the back in the deepest sleep. Existing evidence points to supine-related (lying on your back) OSA being attributable to unfavourable airway position, reduced lung volume, and an inability of airway muscles to compensate adequately.
The position of sleeping face up contributes to drops in blood oxygen levels throughout the night. In the supine position, gravity pulls the airway muscles back, which can lead to more apnoeic events.
COMMON symptoms
Some of the commonly encountered symptoms are:
- Repeated short periods of snoring / noisy and laboured breathing interrupted by gasping or snorting: caused by your tongue, mouth, throat, or airways in your nose vibrating as a breath is taken. It happens because these body parts relax and narrow when you are asleep.
- Witnessed (by a bed partner) spells of apnoeas resulting from complete cessation of airflow due to collapse of the airway and reduced respiratory drive.
- Unrefreshing sleep leading to unexplained daytime sleepiness during work:
- This leads to errors while driving and, thus, a greater risk of collisions in patients who drive as a part of their occupation.
- Sleepy only when seated and relaxed, e.g. watching TV, but eventually sleepiness becomes severe.
- Dry mouth on waking up: caused by excessive mouth breathing
- Waking headaches: present on awakening after sleep based on the apnoea–hypopnea index of at least five episodes per hour of sleep. These are unexplained by other causes like migraines, dehydration, cluster headaches, etc. The ache is due to repeating apnoea, which includes reduced oxygen in the blood and increased blood flow to the brain (due to a build-up of un-excreted carbon dioxide in the blood). However, the exact cause of this type of headache still remains unclear.
- Inability to concentrate on a particular task at hand (e.g. working on a computer or reading a book)
- Nocturia (waking from sleep to urinate): two or more urinations per night, unexplained by other urinary tract diseases like kidney disorders. This is due to co-existing hormonal imbalances and awakenings.
- Choking during sleep: bouts of cough to clear the airway from phlegm.
- Cognitive dysfunction or memory impairment
- Frequent mood swings
- Depression, short temper, grumpiness, personality changes.
- Impotence in males leading to a loss of interest in sex.
How to diagnose sleep apnoea?
Several diagnostic tools, including the STOPBANG and Epworth scoring systems, can be useful.
STOPBANG consists of eight Yes or No questions with a possible highest score of 8. It is easy to use and is a reliable screening tool. Studies have demonstrated that with an increase in the STOPBANG score, there is an increase in the predicted probability and specificity of OSA, which makes the questionnaire ideal for identifying patients at high risk for OSA.
Use STOPBANG to decide if there is a high probability of moderate-severe disease. Label high risk if ‘YES’ to ≥ 3 of the parameters mentioned below and low risk if ‘YES’ to < 3:
- Snoring: Do you snore loudly (louder than talking or loud enough to be heard through closed doors)?
- Tired: Do you often feel tired, fatigued, or sleepy during the daytime?
- Observed: Has anyone observed you stop breathing during your sleep?
- Blood pressure: Are you having or being treated for high blood pressure?
- Body Mass Index: BMI ≥ 35 kg/m2
- Age: > 50 years
- Neck circumference: > 40 centimetres
- Gender: Male
The Epworth Sleepiness Scale is widely used in the field of sleep medicine as a subjective measure of a patient’s sleepiness. An online version of the Epworth Sleepiness Scale can be found on the British Lung Foundation website.
The test lists eight situations in which you rate the tendency to become sleepy on a scale of 0, no chance of dozing, to 3, high chance of dozing. When you finish the test, add up the values of responses.
Your total score is based on a scale of 0 to 24. The scale estimates whether you are experiencing excessive sleepiness that possibly requires medical attention.
There are also more thorough investigations to diagnose OSA, revolving around a sleep study known as polysomnography (PSG), which monitors chest movement, airflow dynamics, heart rate, blood pressure and arterial oxygen saturation.
Worried you have sleep apnoea?
Sleep apnoea symptoms can sometimes be underlying and, more often than not, go undiagnosed. If you suspect that you have one or more of the symptoms above, please visit your local GP. If not diagnosed and treated promptly, sleep apnoea can cause severe complications.
As a leading sleep and respiratory physician specialising in sleep apnoea and sleep-related breathing disorders, I offer consultations to diagnose and treat these conditions. Please contact me if you have any further queries about sleep apnoea symptoms or want further advice on the potential treatments available.
