Sleep apnoea: symptoms, causes and treatment

Key points

• Sleep apnoea is a physical condition, not a mental health one: the upper airway narrows or closes in sleep, so breathing stops and starts [1][2].
• Untreated, it causes exhaustion, poor concentration, irritability and low mood, so it is often mistaken for depression, insomnia or ADHD [1][9].
• The person notices the daytime effects; a bed partner notices the snoring, gasping and pauses in breathing [1][9].
• Obstructive sleep apnoea is the most common form and affects about 1 in 20 people [9].
• Testing starts with a GP and the sleep study is usually done at home. NICE recommends CPAP as the main treatment, with a mandibular advancement splint as the alternative [1][2].

What sleep apnoea is

Sleep apnoea is a condition in which the upper airway narrows or closes during sleep as the muscles relax, causing under-breathing or a complete pause in breathing [1][2]. The person wakes or lightens their sleep to end each episode, usually without remembering it [2]. Obstructive sleep apnoea, the most common form, affects about 1 in 20 people [9].

If you need help now. Samaritans: call 116 123, free, 24/7. Shout: text SHOUT to 85258. NHS 111, then choose the mental health option. Call 999 if anyone is in immediate danger.

It appears in this library for one reason: untreated, it produces exhaustion, low mood, irritability and poor concentration, and is commonly mistaken for depression, insomnia or ADHD [1][9]. The entry exists to help a reader work out whether their tiredness has a treatable physical cause.

Symptoms

Sleep apnoea has two sets of signs. Most people find out through a partner, because the night-time ones are invisible to the sleeper [1][9].

What the person notices

• waking unrefreshed after a full night in bed [9]
• a headache on waking [1][9]
• excessive sleepiness or fatigue during the day [2][9]
• difficulty concentrating or remembering things [1][2][9]
• low mood, mood changes or irritability [1][9]
• broken sleep, or waking to pass urine [2]

What a bed partner notices

• loud snoring [1]
• breathing that stops and starts [1][2]
• gasping, snorting or choking noises [1]
• restless, interrupted sleep [1]

Overlap with mental health

The NHS lists depression among the problems that can follow untreated sleep apnoea, and Asthma + Lung UK says it can cause or worsen depression and mood changes [1][9]. The evidence NICE reviewed found CPAP improved sleepiness, fatigue, vitality and quality of life [6]. NG202 makes no recommendation about mood, and no strong UK evidence shows it replaces treatment for depression [2][6].

Types

NG202 covers three related breathing conditions in people over 16 [2][3]. Central sleep apnoea works differently and is not covered [5].

• Obstructive sleep apnoea/hypopnoea syndrome (OSAHS). The airway narrows or closes as the muscles relax, causing under-breathing (hypopnoea) or a pause (apnoea) [2][5][9].
• Central sleep apnoea. A pause in breathing with no respiratory effort behind it, rather than a blockage [5].
• Obesity hypoventilation syndrome (OHS). Obesity with a raised carbon dioxide level when awake and abnormal breathing in sleep [3].
• COPD-OSAHS overlap syndrome. Sleep apnoea alongside chronic obstructive pulmonary disease, which worsens sleep breathing [5].

In positional OSAHS, breathing events are twice as frequent lying face up [5]. Severity uses the apnoea-hypopnoea index (AHI), events per hour: mild 5 to under 15, moderate 15 to under 30, severe 30 or more [5].

Causes and risk factors

The mechanism is clearer than in most conditions in this library: during sleep the muscles holding the upper airway open relax, and in some people the airway then closes [2]. NICE notes a higher prevalence of obstructive sleep apnoea in people with [2]:

• obesity or overweight, including in pregnancy
• treatment-resistant high blood pressure, or type 2 diabetes
• atrial fibrillation, heart failure, stroke or transient ischaemic attack
• moderate or severe asthma, or polycystic ovary syndrome

Other listed factors include older age, being male, a large neck, large tonsils, smoking, alcohol, back-sleeping and family history [1][9]. Being slim does not rule it out, and neither does the absence of sleepiness: NICE states that not everyone with the condition has it [2].

How it is diagnosed

Diagnosis begins with a GP and is confirmed by a sleep service, usually with equipment worn at home overnight [1][2].

At the GP. NICE advises assessing for obstructive sleep apnoea when someone has two or more of the features listed above, which on NICE’s list also include waking to pass urine and choking during sleep [2]. The Epworth Sleepiness Scale, a short questionnaire on how likely a person is to doze off in everyday situations, is used in the first assessment [2]. NICE is explicit that it measures sleepiness rather than diagnosing sleep apnoea, and must not be the sole basis for referral [2][6].

The test. NICE recommends home respiratory polygraphy first, recording at least four channels overnight, such as oxygen levels, breathing rate, breathing pauses and body position [2][5]. Home oximetry may be used where access is limited [2]. The result is an AHI, which confirms the diagnosis and sets the severity band [2][5]. There is no reliable national figure for waiting times. A diagnosis names a physical cause of tiredness; it does not rule out a mental health condition.

Treatment

NICE recommends lifestyle advice for everyone with obstructive sleep apnoea, and CPAP as the main treatment where symptoms affect daily life [2].

• Lifestyle advice, all severities. Losing weight, stopping smoking, reducing alcohol, better sleep habits [2]. In mild cases with no daytime effects, this is often enough [2].
• CPAP. A machine that pumps air through a mask over the nose, or nose and mouth, to hold the airway open [1][10]. NICE recommends fixed-level CPAP for moderate and severe cases, and for mild cases where symptoms affect daily activities [2]. It is free on the NHS [1].
• Mandibular advancement splint. A device worn over the teeth holding the lower jaw forward [5]. Considered for adults who cannot tolerate CPAP or decline it, if dental health is good [2].
• Positional modifiers. Devices discouraging back-sleeping [5]. Considered in mild or moderate positional cases when other treatments are unsuitable, and unlikely to work in severe cases [2]. The evidence is limited [6].

NG202 recommends no medicine for sleep apnoea itself, and questions about medication belong with a GP [2].

CPAP tolerance. This is the practical difficulty most people meet. Difficulties include mask marks, a blocked or runny nose, dry mouth and eyes, bloating from swallowed air, and claustrophobia [10]. NICE says to consider heated humidification if you get a dry nose or mouth or CPAP-induced rhinitis, and recommends follow-up within a month and supportive help with adherence [2]. Four or more hours a night is the usual benchmark, though NICE notes shorter use still gives some benefit [6].

Living with sleep apnoea

Treatment works only while it is used, so most of what helps is about making it usable.

• Ask the sleep service for help early if your mask leaks, marks your face or feels claustrophobic. Changes to fit, mask type or humidification often help, and you can contact them between appointments [2][10].
• Say if your nose is blocked or runny. Rhinitis makes CPAP harder to tolerate, and CPAP can cause it [2].
• With a splint, expect to be told about mild discomfort, extra saliva and possible longer-term effects on your bite [4].
• Sleep services prioritise people whose job involves vocational driving or safety-critical work, so say so when you are referred. NICE also expects you to be told about the effect of sleepiness on driving and on risk at work [4].
• If you have been treated for depression or insomnia and remain exhausted, tell your GP about snoring, witnessed pauses in breathing or morning headaches [1][2].
• The Sleep Apnoea Trust, which runs an email helpline, and The Sleep Charity on 01302 751 416 offer UK support [7].

When to speak to a professional

Contact a GP if you have two or more of the features NICE lists, particularly if someone has told you your breathing stops and starts at night, or you snore loudly and wake unrefreshed [1][2]. Sleep apnoea can be serious if it is not treated [1]. Tell the GP if you drive for a living, are pregnant or are due to have major surgery, because sleep services prioritise those groups [2].

Driving and the DVLA. You must tell the DVLA if you have confirmed moderate or severe obstructive sleep apnoea syndrome with excessive sleepiness, or another sleep condition causing excessive sleepiness for at least three months [8]. You must not drive until you are free from excessive sleepiness, or symptoms are controlled and you are following any necessary treatment [8]. Car and motorcycle drivers use form SL1 or report online; bus, coach and lorry drivers use form SL1V [8]. Not telling the DVLA can mean a fine of up to £1,000 [8].

If low mood or thoughts of suicide are part of this, get help now rather than waiting for a sleep test. Samaritans: call 116 123. Shout: text SHOUT to 85258. NHS 111, then the mental health option. Call 999 if anyone is in immediate danger.

Common questions

Can sleep apnoea be mistaken for depression?

Untreated sleep apnoea produces low mood, low energy, irritability and poor concentration, which overlap closely with depression [1][9]. What separates them is usually reported by someone else: snoring, gasping and pauses in breathing [1].

How is sleep apnoea tested for in the UK?

A GP takes a sleep history and may use the Epworth Sleepiness Scale before referring on [2]. NICE recommends home respiratory polygraphy first, so most people wear monitoring equipment in their own bed, not in hospital [2].

Does sleep apnoea have to be reported to the DVLA?

It must be reported when obstructive sleep apnoea syndrome is confirmed as moderate or severe with excessive sleepiness [8]. Driving must stop until the sleepiness has gone or symptoms are controlled with treatment [8]. Not reporting it can mean a fine of up to £1,000 [8].

Clinical review pending

References

1. NHS. Sleep apnoea. nhs.uk, accessed August 2026. https://www.nhs.uk/conditions/sleep-apnoea/
2. National Institute for Health and Care Excellence. Obstructive sleep apnoea/hypopnoea syndrome and obesity hypoventilation syndrome in over 16s, section 1: Obstructive sleep apnoea/hypopnoea syndrome. NICE guideline NG202, 2021. https://www.nice.org.uk/guidance/ng202/chapter/1-Obstructive-sleep-apnoeahypopnoea-syndrome
3. National Institute for Health and Care Excellence. Obstructive sleep apnoea/hypopnoea syndrome and obesity hypoventilation syndrome in over 16s, section 2: Obesity hypoventilation syndrome. NICE guideline NG202, 2021. https://www.nice.org.uk/guidance/ng202/chapter/2-Obesity-hypoventilation-syndrome
4. National Institute for Health and Care Excellence. Obstructive sleep apnoea/hypopnoea syndrome and obesity hypoventilation syndrome in over 16s, section 4: Information for people with OSAHS, OHS or COPD-OSAHS overlap syndrome. NICE guideline NG202, 2021. https://www.nice.org.uk/guidance/ng202/chapter/4-Information-for-people-with-OSAHS-OHS-or-COPDOSAHS-overlap-syndrome
5. National Institute for Health and Care Excellence. Obstructive sleep apnoea/hypopnoea syndrome and obesity hypoventilation syndrome in over 16s: Terms used in this guideline. NICE guideline NG202, 2021. https://www.nice.org.uk/guidance/ng202/chapter/Terms-used-in-this-guideline
6. National Institute for Health and Care Excellence. Obstructive sleep apnoea/hypopnoea syndrome and obesity hypoventilation syndrome in over 16s: Rationale and impact. NICE guideline NG202, 2021. https://www.nice.org.uk/guidance/ng202/chapter/Rationale-and-impact
7. Sleep Apnoea Trust. Sleep Apnoea Trust Association. Accessed August 2026. https://sleep-apnoea-trust.org/
8. GOV.UK. Excessive sleepiness and driving. Driver and Vehicle Licensing Agency, accessed August 2026. https://www.gov.uk/sleep-apnoea-and-driving
9. Asthma + Lung UK. What is obstructive sleep apnoea (OSA)? Accessed August 2026. https://www.asthmaandlung.org.uk/conditions/obstructive-sleep-apnoea-osa/what-obstructive-sleep-apnoea-osa
10. Asthma + Lung UK. Continuous Positive Airway Pressure (CPAP). Accessed August 2026. https://www.asthmaandlung.org.uk/conditions/obstructive-sleep-apnoea-osa/continuous-positive-airway-pressure-cpap