Snoring — Causes, Obstructive Sleep Apnoea, CPAP & Treatment Guide — Symptoms, Causes & Treatment | MyMedicPlus

Snoring is a breathing sound produced during sleep by vibration of the soft tissues of the upper airway — particularly the soft palate, uvula, and tonsillar pillars — when airflow is partially obstructed. It is extremely common, affecting approximately 40% of adult men and 24% of adult women. While simple (primary) snoring is benign — a social nuisance affecting bed partners' sleep without health consequences for the snorer — snoring is frequently a symptom of obstructive sleep apnoea (OSA), a serious sleep-related breathing disorder. In OSA, repeated complete or partial collapse of the upper airway during sleep causes apnoeas (complete cessation of breathing, lasting 10 seconds or longer) or hypopnoeas (partial reduction in airflow with arousal), leading to nocturnal oxygen desaturation, sleep fragmentation, and excessive daytime sleepiness. OSA affects 15-30% of adults and is associated with a 2-fold increase in cardiovascular mortality, hypertension, atrial fibrillation, stroke, Type 2 diabetes, and road traffic accidents. Distinguishing primary snoring from OSA is the critical clinical question.

Snoring and OSA result from increased upper airway collapsibility during sleep. During sleep, pharyngeal muscle tone decreases — this is normal; but in susceptible individuals, the anatomically narrow or compliant upper airway partially or completely collapses under the negative pressure of inspiration. Anatomical factors contributing to upper airway narrowing: obesity (the most important modifiable risk factor — fat deposition around the pharynx narrows the airway; a 10% weight gain increases OSA risk 6-fold); enlarged tonsils and adenoids (primary cause in children; also relevant in adults); retrognathia (receding jaw — reduces the pharyngeal space); macroglossia (large tongue); nasal obstruction (nasal polyps, deviated septum, turbinate hypertrophy — forces mouth breathing, altering airway dynamics); high narrow palate; and craniofacial abnormalities. Physiological/neuromuscular factors: alcohol and sedative medications (relax pharyngeal muscles, worsening apnoeas significantly); sleep deprivation itself (worsens upper airway collapse); supine sleeping position (gravity increases tongue and palatal prolapse); and increasing age (pharyngeal muscle tone decreases with age). Risk factors for OSA specifically: male sex (2:1 male:female ratio — though post-menopausal women have similar risk to men); obesity (BMI above 30 — the strongest risk factor); large neck circumference (above 40 cm in women, above 43 cm in men); nasal obstruction; alcohol excess; sedative and opioid medications; hypothyroidism; acromegaly; and pregnancy (OSA worsens progressively through pregnancy).

Primary snoring: loud breathing sounds during sleep; no apnoeas; bed partner disturbed but snorer unaffected — no daytime sleepiness, no nocturnal oxygen desaturation. Obstructive sleep apnoea: loud snoring (often described as a train approaching — very loud, then silent as apnoea occurs, then explosive snort as breathing restarts); witnessed apnoeas (bed partner observes the snorer to stop breathing — the most specific OSA symptom); nocturnal choking or gasping; excessive daytime sleepiness (EDS — the most important symptom; quantified by the Epworth Sleepiness Scale: above 10 abnormal, above 16 severe); unrefreshing sleep despite adequate duration; morning headache (nocturnal hypercapnia); nocturia (recurrent awakening causing increased atrial natriuretic peptide release — up to 80% of OSA patients have nocturia); cognitive impairment (memory, concentration, executive function — major impact on work performance); and mood disturbance (depression, irritability). STOPBANG questionnaire: validated screening tool — Snoring (loud), Tired, Observed apnoeas, blood Pressure (hypertension), BMI above 35, Age above 50, Neck circumference above 40 cm, Gender (male) — each 1 point; 0-2: low risk, 3-4: intermediate, 5-8: high risk OSA.

Sleep studies: Polysomnography (PSG — in-laboratory sleep study): the gold standard — measures brain activity (EEG), eye movements (EOG), muscle tone (EMG), ECG, chest and abdominal respiratory effort, airflow (thermistor, pressure transducer), oxygen saturation (SpO2), body position, and leg movements throughout the night. Apnoea-Hypopnoea Index (AHI): the key metric — number of apnoeas plus hypopnoeas per hour of sleep; mild OSA: AHI 5-14; moderate: 15-29; severe: above 30 per hour. Home sleep apnoea testing (HSAT): portable cardiorespiratory monitoring devices (type 3 monitors) record airflow, respiratory effort, and SpO2 without EEG — widely used as a cost-effective first-line investigation in patients with high pre-test probability of OSA and no significant comorbidities (not suitable for suspected central sleep apnoea, periodic limb movement disorder, or complex cases). Oximetry alone (type 4 monitor): minimum acceptable screening test — oxygen desaturation index (ODI, SpO2 drops above 4% per hour) correlates with AHI; sensitivity moderate. Epworth Sleepiness Scale (ESS): standardised questionnaire quantifying subjective daytime sleepiness. ENT and maxillofacial assessment: nasal endoscopy, Muller's manoeuvre (dynamic assessment of upper airway collapse under negative pressure), and lateral cephalometry — when anatomical causes are being evaluated for surgical correction.

Treatment depends on the severity of OSA (AHI) and symptoms. Primary snoring (no OSA): lifestyle measures; positional therapy; mandibular advancement device. CPAP therapy (continuous positive airway pressure): gold standard for moderate-severe OSA (AHI above 15, or AHI above 5 with significant symptoms). A CPAP machine delivers a constant flow of pressurised air through a nasal or full-face mask during sleep, acting as a pneumatic splint to keep the upper airway open and eliminate apnoeas. Dramatically improves daytime sleepiness (ESS reduction 5-7 points), cognitive function, blood pressure (reduces SBP by 2-3 mmHg), and cardiovascular outcomes. Adherence is the major challenge — modern CPAP devices are quieter and have heated humidifiers and auto-titrating pressure; data monitoring apps allow remote adherence checks. Auto-titrating CPAP (APAP): adjusts pressure breath-by-breath — equivalent efficacy to fixed CPAP with better comfort. BiPAP (bilevel positive airway pressure): for patients unable to tolerate CPAP or with co-existing hypoventilation. Mandibular advancement device (MAD): a custom-fitted dental appliance that protrudes the mandible 5-10 mm, increasing the posterior airspace — effective for mild-moderate OSA and primary snoring; inferior to CPAP for severe OSA but better tolerated; reduces AHI by approximately 50%. Positional therapy: for position-dependent OSA (predominantly supine) — vibrotactile feedback devices or positional pillows reduce supine sleep time; reduces AHI by 30-50% in selected patients. Lifestyle modification: weight loss (5-10% weight reduction reduces AHI by 20-50%); alcohol avoidance before bedtime; smoking cessation; avoiding sedatives and hypnotics. Surgical options: tonsillectomy and adenoidectomy (for tonsillar hypertrophy — particularly effective in children); uvulopalatopharyngoplasty (UPPP) — soft palate surgery; tongue base reduction; maxillomandibular advancement (MMA) osteotomy — highest success rate of any surgical procedure (80-90% AHI reduction); hypoglossal nerve stimulation (Inspire therapy — an implantable upper airway stimulator synchronised with respiration — approved for moderate-severe OSA in patients intolerant of CPAP).

Obstructive sleep apnoea and cardiovascular disease (OSA — present in up to 30% of habitual snorers — causes hypertension in 50% of patients, 2-3 fold increased cardiovascular mortality, atrial fibrillation in up to 50% of OSA cases, metabolic syndrome, and Type 2 diabetes). Road safety risk (OSA-related excessive daytime sleepiness causes 2-4 fold increased road traffic accident risk; in the UK, mandatory DVLA notification is required for uncontrolled OSA causing EDS while driving). Relationship damage and social isolation (partner sleep disruption is a leading cause of separate sleeping arrangements and relationship distress; up to 80% of habitual snorers' bed partners report significant sleep disruption). Pulmonary hypertension and cor pulmonale (from chronic nocturnal hypoxia in severe untreated OSA — a late but preventable complication). Gestational complications (OSA in pregnancy is associated with gestational hypertension, pre-eclampsia, gestational diabetes, and adverse foetal outcomes — screening and CPAP are recommended in pregnant women with high-risk features).

Weight management is the single most effective strategy for both preventing and treating OSA — maintaining a healthy BMI (below 25) substantially reduces upper airway adipose tissue and pharyngeal collapsibility. Regular aerobic exercise improves upper airway muscle tone and reduces OSA severity independently of weight loss. Alcohol avoidance within 3 hours of bedtime: even moderate alcohol intake significantly increases OSA severity by reducing pharyngeal muscle tone — this is the most easily modifiable trigger for snoring. Sedative and hypnotic medications: benzodiazepines, Z-drugs (zopiclone, zolpidem), and opioids all relax pharyngeal muscles and worsen OSA; antihistamines and muscle relaxants have similar effects. Smoking cessation: smokers have 2-3 times higher risk of snoring — tobacco smoke causes upper airway mucosal inflammation and increased secretions, worsening airway narrowing. Sleep position: sleep on your side rather than your back — positional trainers (vibrating devices that deliver a mild stimulus when supine) are available and effective for positional snoring. Treating nasal obstruction (with nasal steroid sprays for allergic rhinitis, or saline irrigation) reduces the negative pressure on the upper airway during nasal breathing and may reduce snoring.

See a GP if you or your bed partner notices: witnessed pauses in breathing during sleep (apnoeas); loud snoring with gasping or choking at night; waking unrefreshed despite apparently adequate sleep; excessive daytime sleepiness (falling asleep at work, while driving, or in conversations); morning headaches; or unexplained high blood pressure. Seek urgent review if: you are a professional driver or pilot and have excessive daytime sleepiness (EDS impairs driving performance equivalently to a blood alcohol level of 0.05%; untreated OSA significantly increases road traffic accident risk — you may be legally required to inform the DVLA in the UK); new atrial fibrillation in a patient with snoring and EDS; or severe oxygen desaturation noticed on any monitoring device. Do not dismiss snoring as merely a social nuisance if it is associated with witnessed apnoeas or daytime symptoms — untreated moderate-severe OSA carries significant cardiovascular morbidity and mortality that is preventable with CPAP therapy.