Sleep & Circadian - Sleep conditions
Sleep apnoea: signs, testing and treatment
Last updated 30 September 2026. How we write this .
Sleep apnoea means your airway narrows or closes in sleep, so breathing stops and starts. Loud snoring, gasping and daytime exhaustion are the clues; a home sleep study confirms it and CPAP is the main treatment.
Start here Sleep apnoea means your airway narrows or closes in sleep, so breathing stops and starts. Loud snoring, gasping and daytime exhaustion are the clues; a home sleep study confirms it and CPAP is the main treatment.
By the end, you will understand What are the signs of sleep apnoea? What is the STOP-Bang questionnaire, and what does my score mean? How is sleep apnoea tested? Key words used in this lesson Placebo An inactive comparison given so that the effect of expectation can be separated from the effect of the intervention itself. Without one, improvement over time cannot be attributed to the treatment. Meta-analysis A statistical method for combining the results of multiple studies into a single estimate. More reliable than any one study, but bounded by the quality of what went into it. Full plain-English glossary
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Sleep apnoea is when your breathing repeatedly stops and starts while you sleep. In the common form, obstructive sleep apnoea, the muscles holding the throat open relax, the airway narrows or closes, and breathing falls or stops until you wake, or your sleep lightens, enough to reopen it. It is hard to spot in yourself. What people usually notice is loud snoring, a partner who has seen them stop breathing, and feeling exhausted however long they sleep.
It is far more common than diagnoses suggest. A 2019 estimate in The Lancet Respiratory Medicine put the number of adults aged 30 to 69 with obstructive sleep apnoea worldwide at about 936 million, of whom 425 million had moderate or severe disease. The NHS says it needs treating because, left alone, it is linked to high blood pressure, stroke, type 2 diabetes, heart disease, low mood and accidents caused by tiredness, including on the road.
What are the signs of sleep apnoea?
Most signs happen at night, which is why a bed partner is often the first to spot them. NICE's guideline NG202 tells clinicians to assess for sleep apnoea when someone has two or more of these:
snoring, or breathing pauses that someone else has seen choking or gasping during sleep sleep that is broken, or that leaves you unrefreshed headaches on waking unexplained sleepiness, tiredness or fatigue in the day getting up in the night to pee poor memory or concentration The NHS links it to obesity, a large neck, getting older, a family history, alcohol, smoking, large tonsils and sleeping on your back. NICE adds that it is more common in people with type 2 diabetes, atrial fibrillation, heart failure, polycystic ovary syndrome, an underactive thyroid, or high blood pressure that does not respond to treatment. Children and young adults can still get it.
What is the STOP-Bang questionnaire, and what does my score mean?
STOP-Bang is an eight-question screening tool. Each yes scores one point:
Snoring: do you snore loudly? Tired: do you often feel tired, fatigued or sleepy in the day? Observed: has anyone seen you stop breathing in your sleep? Pressure: do you have, or are you treated for, high blood pressure? BMI over 35, age over 50, neck over 40 cm around, and male sex A score of 3 or more counts as high risk. Frances Chung's team in Toronto developed it in surgical patients and published the validation in 2008. Of 2,467 people who completed the questions, 177 also had a full sleep study. A score of 3 or more caught 93% of those with moderate sleep apnoea and all of those with severe sleep apnoea. The catch is false alarms: at that cut-off, many people who scored high did not have the condition. A 2012 follow-up in 746 patients found that the chance of moderate or severe sleep apnoea rose from about 36% at a score of 3 to about 60% at 7 or 8.
So treat the score as a nudge, not a verdict. A low score makes moderate or severe sleep apnoea less likely, and a high one means you should get tested. NICE suggests clinicians use STOP-Bang alongside the Epworth Sleepiness Scale, a short questionnaire about how easily you doze off, but not the sleepiness score alone, because not everyone with sleep apnoea feels sleepy.
How is sleep apnoea tested?
If your GP suspects it, they will refer you to a sleep clinic. NICE recommends a home test called respiratory polygraphy first: you wear sensors overnight in your own bed that check things like your breathing and heartbeat. Where that is hard to get, home oximetry, which tracks blood oxygen, may be used instead, and a fuller study called polysomnography is an option if results are negative but symptoms continue. NICE asks sleep services to fast-track people who drive for a living, work in safety-critical jobs, are pregnant, have unstable heart disease or are due major surgery.
The result is reported as the apnoea-hypopnoea index (AHI), the number of times an hour your breathing stops or falls sharply. The NHS grades 5 to 14 as mild, 15 to 30 as moderate, and over 30 as severe.
Do I have to tell the DVLA?
Sometimes, and the rules are specific. Under DVLA guidance you must tell the DVLA if you have confirmed moderate or severe obstructive sleep apnoea with excessive sleepiness, or any sleep condition, including suspected or confirmed mild sleep apnoea, that has caused excessive sleepiness for at least 3 months. You must not drive until you are free from excessive sleepiness, or your symptoms are under control and you are sticking to treatment. Failing to tell the DVLA about a condition that affects driving can bring a fine of up to £1,000, and prosecution if you are involved in an accident. Bus, coach and lorry drivers use a separate form.
In each case the trigger is excessive sleepiness, not the snoring or the diagnosis on its own. If you are unsure whether your sleepiness affects your driving, ask your doctor, and do not drive while you feel drowsy.
Does CPAP work?
For symptoms, yes. A CPAP (continuous positive airway pressure) machine blows a gentle stream of air through a mask over your nose, or nose and mouth, which holds the airway open. NICE recommends offering it, together with lifestyle advice, to everyone with moderate or severe sleep apnoea, and to people with mild sleep apnoea whose symptoms affect daily life. People with mild sleep apnoea and no troublesome symptoms usually do not need treatment beyond lifestyle changes. The NHS provides the machine free if you need it.
The clearest benefit is on sleepiness. A 2003 meta-analysis of 12 randomised trials found that CPAP lowered Epworth sleepiness scores by an average of 2.94 points more than a placebo. In trials of people with severe sleep apnoea who were also very sleepy, the fall was 4.75 points, against 1.10 in the others. In short, the more severe and sleepy you are, the more you notice.
Whether CPAP protects the heart is less clear. The SAVE trial, published in the New England Journal of Medicine in 2016, gave CPAP or usual care to 2,717 adults aged 45 to 75 with moderate or severe sleep apnoea and existing heart disease or stroke. After 3.7 years, heart attacks, strokes and other serious cardiovascular events occurred in 17.0% of the CPAP group and 15.4% of the usual-care group, a difference that could be chance. Most participants were men who were not very sleepy, and on average they used CPAP for 3.3 hours a night. CPAP still reduced snoring and daytime sleepiness and improved mood and quality of life.
What if I cannot get on with CPAP?
The NHS acknowledges that CPAP can feel strange or awkward at first. NICE recommends a first follow-up within a month, support from trained staff, and checks for problems such as a leaking mask, a dry nose and mouth or a blocked nose, with fixes including a different mask, heated humidification or treating the nose. If CPAP still does not work for you, the main alternative is a mandibular advancement splint, a device like a gum shield that holds the lower jaw forward to keep the airway open, suitable for adults with healthy teeth and gums. Other options include devices that stop you sleeping on your back, removal of large tonsils, and in some cases nerve stimulation or other surgery.
Lifestyle changes help at every level: losing weight if you are overweight, stopping smoking, cutting down on alcohol, especially before bed, and sleeping on your side. The NHS warns against sleeping pills unless a doctor recommends them, because they can make sleep apnoea worse. NICE notes that if significant weight loss resolves the problem, treatment can be stopped and the condition reassessed.
If you stop breathing in your sleep, gasp or choke at night, or feel very tired every day, see a GP. Bring the person who has seen it happen, if you can.
This lesson is general education about sleep apnoea, not medical advice. For questions about your own symptoms, treatment or fitness to drive, speak to your GP or sleep clinic.
Related in this classroom Related in other classrooms The studies behind this page Sleep apnoea - NHSObstructive sleep apnoea/hypopnoea syndrome and obesity hypoventilation syndrome in over 16s. 1 Obstructive sleep apnoea/hypopnoea syndrome - NICE guideline NG202, 2021Excessive sleepiness and driving - GOV.UK (DVLA)Estimation of the global prevalence and burden of obstructive sleep apnoea: a literature-based analysis - The Lancet Respiratory Medicine, 2019STOP questionnaire: a tool to screen patients for obstructive sleep apnea - Anesthesiology, 2008High STOP-Bang score indicates a high probability of obstructive sleep apnoea - British Journal of Anaesthesia, 2012Continuous positive airway pressure therapy for treating sleepiness in a diverse population with obstructive sleep apnea: results of a meta-analysis - Archives of Internal Medicine, 2003CPAP for prevention of cardiovascular events in obstructive sleep apnea (SAVE) - New England Journal of Medicine, 2016Sources for this classroom
Educational content only. Not medical advice, diagnosis or treatment. Always consult a qualified healthcare professional before changing your health regimen.