Obstructive sleep apnoea (OSA) is a common and significantly under-diagnosed condition affecting an estimated 1.5 million adults in the UK — though experts believe the true figure may be closer to 4 million once undiagnosed cases are included. It causes repeated interruptions to breathing during sleep, disrupting sleep quality, causing excessive daytime sleepiness, and carrying serious long-term health risks including hypertension, heart disease, and stroke. The good news: it is highly treatable.
What Is Sleep Apnoea?
In obstructive sleep apnoea, the muscles in the throat relax during sleep, causing the soft tissues to collapse and block the upper airway. Breathing stops — for 10 seconds to over a minute — until the brain detects falling oxygen levels and briefly wakes the person to resume breathing. This can happen hundreds of times per night. The person usually has no memory of these awakenings but wakes exhausted despite spending adequate time in bed.
There are three main types:
- Obstructive sleep apnoea (OSA) — the most common; airway physically collapses
- Central sleep apnoea (CSA) — the brain fails to send the right signals to breathing muscles; less common; associated with heart failure and opioid use
- Mixed (complex) sleep apnoea — a combination of both types
Sleep Apnoea Symptoms
Symptoms Noticed by the Person
- Excessive daytime sleepiness (EDS) — falling asleep in inappropriate situations (watching TV, in meetings, while driving); rated using the Epworth Sleepiness Scale
- Waking unrefreshed — never feeling truly rested regardless of how long you sleep
- Morning headaches — from overnight carbon dioxide retention and poor sleep quality
- Difficulty concentrating and memory problems
- Irritability and mood changes
- Frequent night-time urination (nocturia) — OSA causes atrial natriuretic peptide release, mimicking full bladder
- Waking with a dry mouth or sore throat
- Reduced libido
- Waking gasping or choking
Symptoms Noticed by a Partner
- Loud, disruptive snoring — though not all snorers have OSA, and not all OSA causes snoring
- Witnessed apnoeas — the partner sees breathing stop and then resume with a gasp or snort; this is the most specific symptom
- Restless sleep — frequent moving, kicking, tossing and turning
Risk Factors
- Obesity — the strongest modifiable risk factor; fat deposits around the neck increase airway collapsibility; a neck circumference >40cm (men) or >35cm (women) is a significant risk factor
- Male sex — men are 2–3 times more likely than pre-menopausal women; women’s risk increases after menopause
- Age — risk increases with age as muscle tone reduces
- Anatomical factors — large tonsils, small jaw (retrognathia), large tongue, narrow airway
- Alcohol — relaxes upper airway muscles; worsens severity significantly; avoid within 3–4 hours of sleep
- Sedatives and sleeping tablets — increase airway muscle relaxation
- Smoking — causes inflammation and fluid retention in the upper airway
- Family history — genetic predisposition to anatomical risk factors
- Hypothyroidism and acromegaly — secondary causes of OSA
Health Consequences of Untreated Sleep Apnoea
- Hypertension — OSA is a major secondary cause of resistant hypertension; found in 50% of people with high blood pressure
- Cardiovascular disease — atrial fibrillation, heart attack, and stroke risk all significantly elevated
- Type 2 diabetes — overnight oxygen desaturation impairs insulin sensitivity
- Road traffic accidents — people with untreated severe OSA have 3–7 times the accident rate of normal sleepers; DVLA reporting obligations apply
- Depression and cognitive impairment
- Pulmonary hypertension — in severe untreated cases
Diagnosis
See your GP if you have excessive daytime sleepiness, are told you snore loudly, or have witnessed apnoeas. Your GP may use the STOP-BANG questionnaire or Epworth Sleepiness Scale to assess risk before referring to a sleep clinic.
Sleep Studies
- Home sleep test (limited channel study) — the most common NHS diagnostic approach; a portable device worn overnight at home records oxygen levels, airflow, respiratory effort, and heart rate; measures the AHI (apnoea-hypopnoea index)
- In-lab polysomnography (PSG) — gold standard; overnight in a sleep laboratory; records brain waves, eye movements, muscle activity, heart rate, breathing, and oxygen; reserved for complex or equivocal cases
OSA Severity by AHI
| AHI (events/hour) | Severity |
|---|---|
| 5–14 | Mild OSA |
| 15–29 | Moderate OSA |
| ≥30 | Severe OSA |
NHS Treatment for Sleep Apnoea
CPAP Therapy (Continuous Positive Airway Pressure)
CPAP is the gold-standard treatment for moderate-severe OSA and for mild OSA causing significant symptoms. A bedside machine delivers pressurised air through a mask (nasal, nasal pillow, or full-face) worn during sleep. The airflow acts as a pneumatic splint, keeping the upper airway open. Results are transformative for most patients — daytime sleepiness resolves, blood pressure improves, and cardiovascular risk reduces.
CPAP is free on the NHS for eligible patients. The equipment is provided and maintained by the sleep service. Modern CPAP machines are quiet (25–30 dB — quieter than a whisper) and have data recording to monitor compliance. The biggest challenge is adherence — getting used to the mask takes time.
Mandibular Advancement Device (MAD)
A custom-made dental device that holds the lower jaw forward during sleep, enlarging the airway. Recommended for mild-moderate OSA or for those who cannot tolerate CPAP. Less effective than CPAP for severe OSA but many patients find it more comfortable. Available on NHS in some areas via dental or sleep services.
Positional Therapy
OSA is often worse when sleeping on the back (supine). Positional devices (vibrating alarms, specialist pillows, or even tennis balls sewn into a shirt) encourage side-sleeping. Effective for purely positional OSA.
Lifestyle Changes
- Weight loss — the most impactful lifestyle change; even 10% weight loss can reduce AHI by 26%; some patients achieve remission; GLP-1 medications (Wegovy/Mounjaro) are now FDA-approved specifically for OSA in obese patients
- Avoid alcohol — especially in the 3–4 hours before sleep
- Stop smoking
- Avoid sedatives — sleeping tablets and antihistamines worsen OSA
- Sleep on your side
DVLA and Driving with Sleep Apnoea
If you have OSA causing excessive daytime sleepiness, you have a legal duty to tell the DVLA and must stop driving until your symptoms are controlled with treatment (usually CPAP). Once on effective CPAP and no longer excessively sleepy, you can resume driving — you do not need to inform DVLA if OSA is well-controlled and not causing sleepiness. Lorry/bus/taxi drivers face stricter rules — always check DVLA guidance.
This article is for informational purposes only. If you think you may have sleep apnoea, see your GP. Do not drive if you are excessively sleepy — it is dangerous and may be illegal.
Related Health Guides on YourHealthXpert
Explore these related NHS-aligned health guides:
- High Blood Pressure Guide — Sleep apnoea is a major cause of treatment-resistant hypertension; learn how treating sleep apnoea improves blood pressure control.
- Heart Attack Guide — Untreated sleep apnoea significantly increases heart attack risk; understand the cardiovascular connection and NHS care pathway.
- Type 2 Diabetes Guide — Sleep apnoea and type 2 diabetes are closely linked through insulin resistance; learn about managing both conditions.
- Anxiety & Depression Guide — Poor sleep from sleep apnoea worsens mental health; understand the NHS support available for sleep-related mood disorders.
- Weight Loss Guide — Excess weight is the primary cause of obstructive sleep apnoea; even modest weight loss can reduce AHI significantly.
- Stroke Guide — Sleep apnoea doubles stroke risk through nocturnal oxygen dips and blood pressure surges; learn the warning signs and NHS pathway.