The short answer
Obstructive sleep apnoea is when the throat repeatedly closes during sleep, stopping breathing for seconds at a time. Signs are loud snoring, gasping or choking, pauses in breathing and heavy daytime tiredness. It's common and often undiagnosed. A GP can refer you for a home sleep test, and treatment, often a CPAP machine, is free on the NHS and works well.
On this page
What happens in sleep apnoea?
When you fall asleep, the muscles in your throat relax. In obstructive sleep apnoea the airway narrows so much that it partly or fully closes, and breathing stops for 10 seconds or more. Oxygen levels fall, the brain briefly wakes you to reopen the airway, often with a snort or gasp, and you fall asleep again without remembering. This can happen dozens of times an hour, so sleep is broken all night.
How common is it?
Much more common than diagnoses suggest. A 2019 estimate found that about 936 million adults aged 30 to 69 worldwide have at least mild obstructive sleep apnoea, and 425 million have moderate to severe apnoea, which usually needs treatment. It’s more likely if you are overweight, have a large neck, are older, drink alcohol, smoke, sleep on your back or have family members with it.
What are the signs?
At night, often noticed by a partner:
- loud snoring,
- breathing that stops and starts,
- gasping, snorting or choking noises,
- waking a lot.
In the day:
- feeling very tired or falling asleep without meaning to,
- headaches on waking,
- poor concentration and mood swings.
Why does it matter?
Untreated, sleep apnoea is linked to high blood pressure, stroke, type 2 diabetes, heart disease and depression, according to the NHS. Sleepiness also raises the risk of accidents, including on the road. See sleep and the heart.
How is it diagnosed?
If a GP suspects sleep apnoea, they may ask you to fill in a sleepiness questionnaire and refer you to a sleep clinic. Most people are given a small device to wear overnight at home that records breathing, oxygen levels and heart rate. The result is given as the AHI (apnoea-hypopnoea index), the number of times breathing stops or becomes shallow per hour:
| AHI | Severity |
|---|---|
| 5 to 14 | Mild |
| 15 to 30 | Moderate |
| Over 30 | Severe |
What are the treatments?
- Lifestyle changes: losing weight if you’re overweight, cutting down on alcohol, especially in the evening, stopping smoking and sleeping on your side. These may be enough for mild apnoea.
- CPAP: a machine that blows air gently through a mask to keep the airway open. It’s the main treatment for moderate and severe apnoea, recommended by NICE and free on the NHS. It improves sleep and daytime sleepiness, but only if you use it every night. Masks can be adjusted if it’s uncomfortable.
- Mandibular advancement device: a gum-shield-like device that holds the lower jaw forward, an option for mild apnoea or for people who can’t use CPAP.
- Surgery, for example removing large tonsils, in some cases. A newer option for some people is an implant that stimulates the nerve controlling the tongue.
Avoid sleeping pills and sedatives unless a doctor recommends them, as they can make apnoea worse.
What about snoring without apnoea?
Snoring alone isn’t harmful, though it can disrupt a partner’s sleep. Losing weight, cutting alcohol, sleeping on your side and treating a blocked nose can help. Pharmacy devices such as nasal strips help some people. If snoring is loud and you feel tired in the day, see a GP to rule out apnoea.
Driving
If you are diagnosed with moderate or severe sleep apnoea with excessive sleepiness, you must tell the DVLA and must not drive until your symptoms are under control. Treatment usually allows people to keep driving. Check the GOV.UK guidance.
Keep reading
- Restless legs syndrome: causes, self-help and treatment
What restless legs syndrome feels like, its links with iron, pregnancy and kidney disease, what you can do yourself and the treatments a GP may offer.
- Shift work and sleep: how to sleep after night shifts
Why night and early shifts disrupt sleep, the health risks linked to shift work, and practical ways to sleep around a rota, using light, naps and caffeine.
- Jet lag: how to reduce it and recover faster
Why jet lag happens, why flying east is usually harder, how to adjust using light, sleep and meal times, and what the evidence says about melatonin.
Common questions
Is all snoring sleep apnoea?
No. Plenty of people snore without apnoea. Snoring is more likely to be apnoea if it's loud, broken by silences followed by gasps or snorts, and you feel very tired in the day despite enough time in bed.
Do I have to tell the DVLA about sleep apnoea?
You must tell the DVLA if you have confirmed moderate or severe obstructive sleep apnoea with excessive sleepiness, or another sleep condition that has caused excessive sleepiness for at least 3 months. You must not drive until the sleepiness is under control and you are following treatment. You can be fined up to £1,000 for not telling them.
Can sleep apnoea go away?
Sometimes. Losing weight, cutting down on alcohol and stopping smoking can greatly improve it, and mild apnoea may disappear. Many people with moderate or severe apnoea need ongoing treatment.
What is the Epworth score?
The Epworth Sleepiness Scale is a short questionnaire about how likely you are to doze off in eight everyday situations. A GP may use it to judge how sleepy you are in the day.
References
- NHS. Sleep apnoea.nhs.uk
- NICE. Obstructive sleep apnoea/hypopnoea syndrome and obesity hypoventilation syndrome in over 16s (NG202), 2021.nice.org.uk
- Benjafield AV et al. Estimation of the global prevalence and burden of obstructive sleep apnoea: a literature-based analysis. Lancet Respiratory Medicine, 2019.pubmed.ncbi.nlm.nih.gov
- GOV.UK. Excessive sleepiness and driving.gov.uk
- NHS. Snoring.nhs.uk
First published 4 November 2026. Spotted an error? Tell us and we'll correct it. Read our editorial policy.