Some smartwatches can flag signs of possible sleep apnoea, but none can diagnose it. Features on the Apple Watch and the Samsung Galaxy Watch, cleared by the US Food and Drug Administration, look for signs of moderate to severe obstructive sleep apnoea. False alarms are rare, no alert does not rule it out, and a sleep study confirms the diagnosis.
What is sleep apnoea?
In obstructive sleep apnoea the upper airway narrows or closes during sleep. Breathing pauses completely (an apnoea) or becomes shallow (a hypopnoea) for 10 seconds or more, many times an hour. The number of these events per hour is the apnoea hypopnoea index, or AHI. Fewer than 5 is normal, 5 to 14 is mild, 15 to 29 is moderate and 30 or more is severe (NICE NG202).
It is common and often missed. One global estimate puts the number of adults aged 30 to 69 with sleep apnoea at 936 million, 425 million of them with moderate or severe disease (Benjafield, 2019). A landmark American study found that undiagnosed sleep-disordered breathing was common, especially in men (Young, 1993).
What does the Apple Watch look for?
The Apple Watch uses its motion sensor to pick up the small movements of breathing and counts what Apple calls Breathing Disturbances each night. Every 30 days, if at least 10 nights were recorded and at least half of them showed raised levels, the watch sends a notification of possible sleep apnoea. Apple's paper describes the feature on Series 9 and later and Ultra 2, and states that it is not meant for people already diagnosed. It is also clear that "Breathing Disturbances aren’t equivalent to the AHI" (Apple, 2024). The US Food and Drug Administration cleared the feature in September 2024 (FDA).
How accurate is it?
Apple tested the finished feature in 1,499 people who wore the watch for up to 30 nights alongside home sleep tests scored by sleep technologists (Apple, 2024).
- False alarms were very rare. No one with normal breathing received an alert, and 91% of people with mild sleep apnoea correctly received none.
- It picked up 89.1% of people with severe sleep apnoea.
- It picked up only 43.4% of people with moderate sleep apnoea, so more than half of that group got no alert.
Apple chose this balance deliberately, to keep false alarms low. So an alert is worth acting on, but no alert should not reassure you if you have symptoms.
What about Samsung, rings and other trackers?
Samsung's sleep apnoea feature received De Novo authorisation from the US Food and Drug Administration in February 2024. It is for adults over 22 who have not been diagnosed, and looks for signs of moderate to severe obstructive sleep apnoea across two nights of more than four hours' sleep within ten days (Samsung, 2024).
Many rings and bands report blood oxygen or breathing measures overnight. Repeated dips in oxygen can be a clue worth mentioning to a doctor. Unless the maker has validated the feature for sleep apnoea and published how well it works, treat it as a general reading, and see our guide to how accurate sleep trackers are for what the wider evidence shows.
What confirms sleep apnoea?
The diagnosis needs a sleep study. American guidance is that questionnaires and prediction tools should not be used to diagnose sleep apnoea without a sleep test (AASM, 2017). NICE recommends a home respiratory study as the first test for suspected obstructive sleep apnoea, and a full overnight study if the result is negative but symptoms continue (NICE NG202). Our guide to home and overnight sleep studies explains the difference.
What should I do if my watch alerts me?
Book an assessment rather than wait for more alerts. Write down what you notice, such as snoring, waking with a dry mouth or headache, or sleepiness in the day, and ask anyone who shares your room whether they have heard you stop breathing. The signs are set out in signs of sleep apnoea in adults.
If you drive and feel sleepy at the wheel, stop driving until you have been assessed. UK rules say you must tell the DVLA if you are diagnosed with moderate or severe sleep apnoea with excessive sleepiness (GOV.UK).
Testing at The Wellness
If your watch has alerted you, or you have symptoms, our Sleep Clinic starts with a Sleep Consultation at £450, which includes STOP-Bang and Epworth scoring (Chung, 2016) and a clear answer on whether you need a study. The Home Sleep Study is £1,395, and we review your watch data alongside it. The Sleep Clinic programme, which most people choose, is £2,995 and adds a consultation with a respiratory sleep consultant, blood tests chosen for your sleep and a plan reviewed at three months.
There are established treatments, from CPAP to mouth splints (NICE NG202). Left alone, severe disease has been linked with heart attack, stroke and road crashes (Marin, 2005; Tregear, 2009). Book a sleep consultation to find out where you stand.
This article is general information and does not replace a consultation. If you are falling asleep at the wheel, stop driving until you have been assessed. If you have chest pain, severe breathlessness or signs of a stroke, call 999.
Frequently asked questions
Can Apple Watch detect sleep apnoea?
It can flag signs of moderate to severe sleep apnoea, but it does not diagnose it. In Apple’s validation study false alarms were rare, but the watch missed more than half of the people with moderate sleep apnoea. A sleep study confirms the diagnosis.
My watch has never warned me. Can I still have sleep apnoea?
Yes. In Apple’s study the watch flagged 43.4% of people with moderate sleep apnoea and 89.1% of people with severe sleep apnoea, so many people with the condition get no alert. Symptoms such as loud snoring, pauses in breathing and daytime sleepiness matter more than the absence of an alert.
Can a smart ring detect sleep apnoea?
A ring can record blood oxygen and heart rate overnight, and repeated dips in oxygen can be a clue. Treat any such reading as a reason to talk to a doctor rather than as a result. Only a sleep study measures the pauses in breathing that define sleep apnoea.
What test confirms sleep apnoea?
You need a sleep study. NICE recommends a home respiratory study as the first test for most adults, and an overnight study in a sleep centre if the home test is negative but symptoms continue.
Speak to the team about sleep
See what we offer, then book when it suits you.