What Are the Warning Signs of Sleep Apnoea?
The warning signs of sleep apnoea can appear during both the night and the day. A person may snore loudly, stop breathing for short periods, gasp or choke in their sleep and wake repeatedly without knowing why. During the day, they may feel unusually sleepy, struggle to concentrate or wake with a headache despite spending enough time in bed.
Sleep apnoea is not the only possible cause of snoring or tiredness. However, repeated breathing pauses, choking noises and significant daytime sleepiness should not be ignored. Speak to your GP if you recognise this pattern in yourself or someone close to you.
Do not drive if you are struggling to stay awake or feel that sleepiness could affect your control of a vehicle. If someone is unresponsive and not breathing normally, call 999 immediately.
The short answer
Common warning signs of sleep apnoea include:
breathing that repeatedly stops and starts during sleep
loud and persistent snoring
gasping, snorting or choking noises
waking frequently or sleeping restlessly
feeling unrefreshed after a full night in bed
excessive sleepiness or fatigue during the day
morning headaches
difficulty concentrating or remembering things
irritability, low mood or other mood changes
waking during the night to pass urine
NICE advises that obstructive sleep apnoea should be considered when a person has two or more recognised features, including snoring, witnessed breathing pauses, unrefreshing sleep, waking headaches, unexplained sleepiness, choking during sleep, disturbed sleep, waking to pass urine or problems with memory and concentration.
The pattern matters more than one symptom on its own. Snoring is common and does not automatically mean that somebody has sleep apnoea.
What is sleep apnoea?
Sleep apnoea is a condition in which breathing repeatedly stops and starts during sleep. The most common type is obstructive sleep apnoea.
Obstructive sleep apnoea happens when the upper airway narrows or closes as the muscles relax during sleep. Breathing may stop completely for a short period, which is called an apnoea, or become much shallower, which is called a hypopnoea.
The brain detects the change and briefly brings the person into lighter sleep so that the airway reopens. Normal breathing then returns, often with a gasp, snort or choking sound. The person may fall back into deeper sleep without remembering that they woke.
This cycle can happen many times during the night. The repeated interruptions can prevent restorative sleep and may reduce oxygen levels. That is why the most obvious daytime symptom can be tiredness rather than a remembered breathing problem.
Warning signs during sleep
Breathing stops and starts
Witnessed pauses in breathing are one of the clearest warning signs. A partner, relative or friend may notice that the person becomes quiet after a period of snoring, appears not to breathe and then restarts with a gasp or snort.
The person experiencing the episodes will often have no memory of them. This is why information from somebody who has observed the person sleeping can be valuable during a GP appointment.
Not every unusual breath is sleep apnoea. Breathing patterns can vary during sleep, and a diagnosis cannot be made by watching alone. Repeated pauses combined with snoring, choking or daytime sleepiness are more concerning than an isolated noise or movement.
Loud and persistent snoring
Snoring is caused by tissues in the mouth, throat or nose vibrating as air moves through a narrowed space. It is very common and usually does not mean that a person has a serious condition.
Snoring becomes more suggestive of sleep apnoea when it is loud, happens on most nights and is interrupted by silence, choking, snorting or gasping. Concern is also greater when the person wakes unrefreshed or is very sleepy during the day.
Quiet sleep does not completely rule sleep apnoea out. The decision to investigate depends on the full pattern of symptoms, medical history and risk factors.
Gasping, snorting or choking
A sudden gasp or choking noise may happen when the airway reopens after a breathing pause. Some people wake with the sensation that they are choking or cannot catch their breath.
Repeated choking or gasping during sleep should be discussed with a GP, particularly when it happens alongside loud snoring, witnessed breathing pauses or significant daytime tiredness.
Breathlessness while fully awake can have different causes. Sudden severe difficulty breathing, chest pain, blue or grey lips or skin, confusion or loss of consciousness requires emergency help rather than a routine sleep assessment.
Frequent waking and restless sleep
Some people with sleep apnoea wake repeatedly, move frequently or feel that their sleep is light and broken. Others do not remember waking but notice that they never feel properly rested.
Sleep fragmentation can also present as insomnia. A person may believe that they simply cannot stay asleep when repeated breathing events are contributing to the problem.
Restless sleep has many possible explanations, including stress, pain, alcohol, noise, temperature, restless legs and other sleep disorders. It becomes more suspicious when combined with breathing noises, pauses or daytime sleepiness.
Waking frequently to pass urine
Waking during the night to pass urine is called nocturia. It can occur with sleep apnoea and is included by NICE among the features that may support assessment.
Nocturia is not specific to sleep apnoea. It can also relate to fluid intake, bladder or prostate problems, diabetes, pregnancy, medicines and other health conditions. A clinician should consider the complete picture rather than treating it as proof of a sleep disorder.
Warning signs during the day
Excessive daytime sleepiness
Excessive sleepiness is more than feeling a little tired after a late night. It may involve struggling to stay awake while reading, watching television, sitting in a meeting or travelling as a passenger. Some people fall asleep at work or during conversations.
The most urgent risk arises when sleepiness affects driving or the use of machinery. Do not begin or continue a journey if you are fighting sleep, having difficulty concentrating or have started nodding off.
Daytime tiredness has many other possible causes, including insufficient sleep, anaemia, thyroid problems, low mood, medicines, alcohol and other sleep conditions. The combination of daytime sleepiness with loud snoring or witnessed breathing pauses makes sleep apnoea more likely and should prompt medical assessment.
Feeling unrefreshed after enough time in bed
A person with sleep apnoea may spend seven, eight or more hours in bed but wake feeling as though they have barely slept. Repeated brief arousals prevent the normal progression through restorative stages of sleep.
Feeling unrefreshed occasionally is common. It becomes more concerning when it happens consistently and is accompanied by snoring, choking, morning headaches or sleepiness throughout the day.
Morning headaches
Headaches on waking are a recognised feature of sleep apnoea. They may relate to disturbed sleep, changes in oxygen or carbon dioxide levels and other factors.
Morning headaches can also arise from dehydration, teeth grinding, migraine, poor sleep posture and many other causes. Persistent or changing headaches should be assessed on their own merits rather than assumed to be sleep apnoea.
Poor concentration or memory
Repeatedly disrupted sleep can affect attention, reaction time, short term memory and decision making. A person may make more mistakes, take longer to complete familiar tasks or find it difficult to follow a conversation.
These changes can develop gradually. They may be mistaken for stress, ageing or a lack of motivation, particularly when nobody has noticed the person's breathing during sleep.
Irritability and mood changes
Poor sleep can affect emotional regulation. Irritability, low mood, reduced patience and mood swings can occur when sleep apnoea repeatedly interrupts the night.
These symptoms are not unique to sleep apnoea and deserve a broad assessment. Seek urgent mental health support if there is an immediate risk of harm, regardless of whether poor sleep may be contributing.
Is snoring always a sign of sleep apnoea?
No. Snoring is common and many people who snore do not have sleep apnoea.
The more concerning pattern is:
loud snoring on most nights
repeated silent pauses in breathing
gasping, choking or snorting as breathing restarts
unrefreshing sleep
excessive daytime sleepiness
A person can also have sleep apnoea without fitting the stereotype of a very loud snorer. Symptoms, medical history and a proper sleep study are needed to make the diagnosis.
Who is more likely to develop obstructive sleep apnoea?
Sleep apnoea can affect people of different ages and body sizes. Factors linked with a higher chance include:
living with overweight or obesity
having a larger neck
getting older
having close relatives with sleep apnoea
drinking alcohol, particularly near bedtime
smoking
having large tonsils or adenoids
sleeping on the back
NICE also identifies a higher prevalence among people with certain health conditions, including treatment resistant high blood pressure, type 2 diabetes, atrial fibrillation, stroke, chronic heart failure, polycystic ovary syndrome and an underactive thyroid.
Risk factors do not confirm the condition, and their absence does not rule it out. Symptoms should be assessed without blame or assumptions about body size.
Can sleep apnoea affect people who are not overweight?
Yes. Body weight is one important factor, but it is not the only one. The shape of the jaw and airway, tonsil size, age, family history, alcohol, smoking and other medical conditions may contribute.
A person should not dismiss witnessed breathing pauses or severe daytime sleepiness simply because they are not overweight. Equally, somebody living with obesity should not assume that all tiredness is caused by sleep apnoea. Testing is needed to establish the diagnosis.
When should you speak to a GP?
Arrange a GP appointment if:
somebody has seen your breathing stop and start while you sleep
you repeatedly gasp, snort or choke during sleep
you are consistently very tired or sleepy during the day
loud snoring is accompanied by unrefreshing sleep or morning headaches
tiredness is affecting work, concentration, relationships or daily activities
you are concerned that sleepiness could affect driving
If possible, ask the person who noticed the symptoms to describe what they saw. They may attend the appointment with you if that would help. Note how often the episodes happen, whether they are worse after alcohol or when sleeping on your back, and how sleepiness affects you during the day.
Do not delay the appointment while trying to collect perfect evidence. A phone recording, watch or sleep application cannot diagnose sleep apnoea. Clinicians use the history and an appropriate sleep study.
When is it an emergency?
The usual sleep apnoea pattern involves short breathing pauses followed by breathing restarting. It does not require an ambulance every time a familiar brief pause occurs.
Call 999 if a person is unresponsive and is not breathing normally. Follow the call handler's instructions and begin cardiopulmonary resuscitation if advised.
Call 999 for sudden blue or grey lips, tongue, face or skin, severe difficulty breathing, severe chest pain, collapse or another life threatening emergency. These signs should not be assumed to be routine sleep apnoea.
Sleep apnoea and driving
Sleepiness can seriously impair concentration and reaction time. Do not drive if you are struggling to stay awake, nodding off or believe your symptoms could affect safe control of the vehicle.
People in England, Scotland and Wales should check the current DVLA requirements. Government guidance includes specific notification rules for confirmed obstructive sleep apnoea with excessive sleepiness and for some other conditions that cause persistent excessive sleepiness.
Northern Ireland uses the Driver and Vehicle Agency rather than DVLA. Drivers must report a medical condition that is likely to affect safe driving. If you are unsure, stop driving and ask your doctor and the relevant licensing authority for advice.
Do not wait for a sleep clinic appointment before stopping an unsafe journey. Opening a window, turning up music or relying on caffeine does not make it safe to drive while excessively sleepy.
How is sleep apnoea diagnosed?
A GP may ask about snoring, observed breathing pauses, sleep quality, daytime sleepiness, medicines, alcohol and wider health. They may also consider other possible causes of fatigue.
If sleep apnoea is suspected, the GP may refer the person to a specialist sleep service. Testing commonly records breathing, oxygen levels and heart rate during sleep. Many people can complete the test at home using equipment supplied by the service, although some need an overnight hospital assessment.
NICE recommends home respiratory polygraphy for adults with suspected obstructive sleep apnoea. Home oximetry may sometimes be considered where access is limited. More detailed testing may be needed if the first test is negative but significant symptoms continue.
The apnoea hypopnoea index records how often breathing stops or becomes significantly reduced per hour of sleep. An index from 5 to below 15 is generally described as mild, from 15 to below 30 as moderate, and 30 or more as severe. The result must be interpreted with symptoms and the wider clinical assessment.
What treatment might be offered?
Treatment depends on the cause, severity, symptoms and individual health. Options may include:
continuous positive airway pressure, usually called CPAP
a mandibular advancement device that helps hold the airway open
support with weight management where appropriate
reducing alcohol, particularly before bed
stopping smoking
changing sleep position in positional sleep apnoea
treatment for enlarged tonsils or another airway problem
surgery or specialist procedures in selected cases
CPAP uses gentle air pressure through a mask to help prevent the airway becoming too narrow during sleep. The NHS advises that it can improve sleep quality, reduce tiredness and lower the risk of problems linked with sleep apnoea.
Lifestyle changes can help some people, but they should not be used as a reason to postpone assessment when warning signs are present. Do not use another person's CPAP equipment or buy an unregulated treatment without clinical advice.
Sleep apnoea, body weight and Keltoi
Obstructive sleep apnoea is more common among people living with overweight or obesity, but it is not caused by a lack of effort and it does not affect only people in larger bodies.
Poor sleep and daytime fatigue can make meal planning, activity and other healthy routines more difficult. Weight management may form part of an agreed treatment plan, but losing weight is not a substitute for a sleep assessment or appropriate treatment.
Keltoi Wellness provides doctor led remote weight management support for eligible adults across the UK. The website questionnaire may give Dr Waqar Ahmed a snapshot of a patient's health, but it does not diagnose sleep apnoea or decide whether treatment is suitable.
Tell Dr Ahmed if you have diagnosed sleep apnoea, use CPAP, are awaiting a sleep study or experience significant daytime sleepiness. Clinical and prescribing decisions remain with Dr Ahmed. Patients with warning signs should also contact their GP because investigation and sleep service referral may be required.
Do not ignore the pattern
One poor night's sleep or occasional snoring does not prove that somebody has sleep apnoea. The warning pattern is repeated breathing pauses, gasping or choking, loud persistent snoring and sleep that does not leave the person refreshed.
Daytime sleepiness is especially important because it can affect work, concentration and road safety. Speak to your GP if the symptoms fit, and do not drive when you cannot stay alert.
Sleep apnoea is treatable. Recognising the warning signs is the first step towards an appropriate assessment and safer, more restorative sleep.
Frequently asked questions
What is the biggest warning sign of sleep apnoea?
Repeated pauses in breathing witnessed by another person are among the clearest warning signs, particularly when followed by gasping or choking. Loud snoring and excessive daytime sleepiness strengthen the reason to seek assessment.
Can I have sleep apnoea without knowing?
Yes. Many people do not remember waking when their breathing changes. A partner or relative may notice the pauses first, while the person affected notices only tiredness, headaches or poor concentration.
Does snoring mean I have sleep apnoea?
No. Snoring is common and often occurs without sleep apnoea. Snoring becomes more concerning when breathing repeatedly stops, choking or gasping occurs, or the person is very sleepy during the day.
Can a smartwatch tell me if I have sleep apnoea?
A wearable device or sleep application may notice patterns that encourage someone to seek advice, but it cannot replace a clinical assessment and an appropriate diagnostic sleep study.
Should I record someone sleeping?
A brief recording may help describe an observed breathing pattern, provided the person agrees and it can be obtained safely. Do not delay contacting the GP because you do not have a recording. A recording cannot confirm the diagnosis.
Is waking with a dry mouth a sign of sleep apnoea?
It can occur when a person breathes through their mouth or snores, but it is not specific to sleep apnoea. It is more meaningful when combined with breathing pauses, choking, loud snoring or daytime sleepiness.
Can sleep apnoea go away if I lose weight?
Weight reduction may improve obstructive sleep apnoea for some people, but it does not guarantee that the condition has resolved. Continue prescribed treatment and follow up until the responsible sleep clinician confirms whether anything should change.
Should I stop driving if I think I have sleep apnoea?
Stop driving if excessive sleepiness makes it difficult to concentrate or stay awake. Ask your doctor and the relevant licensing authority for advice. Great Britain uses DVLA, while Northern Ireland uses DVA.
What happens during a sleep apnoea test?
Many tests are completed at home using equipment that records breathing, oxygen levels and heart rate overnight. Some people need a more detailed hospital sleep study. The sleep service explains which test is appropriate.
Can sleep apnoea be treated?
Yes. Treatment may include CPAP, an oral device, lifestyle changes or selected specialist procedures. The most suitable option depends on the test result, symptoms, health and anatomy.
Sources and further reading
NHS: Sleep apnoea
NICE: Obstructive sleep apnoea and hypopnoea syndrome in people over 16
NICE: Home testing devices for obstructive sleep apnoea
NHS: Snoring
Royal Papworth Hospital: Obstructive sleep apnoea
GOV.UK: Excessive sleepiness and driving
nidirect: How to tell DVA about a medical condition
NHS: First aid and abnormal breathing
Last updated: August 2026
Disclaimer: This article provides general information for adults and does not diagnose sleep apnoea or replace advice from a GP or sleep specialist. Call 999 if someone is unresponsive and not breathing normally. Do not drive if excessive sleepiness could affect safe control of a vehicle.