Snoring

Snoring is a sound produced by vibration of the soft tissues of the upper airway (soft palate, uvula, tonsils, tongue base, pharyngeal walls) during sleep, when airflow is turbulent through a narrowed pharyngeal airway. Snoring is a symptom and not a disease, and ranges from benign primary snoring to a marker of obstructive sleep apnoea (OSA).

• Prevalence: habitual snoring in about 20 to 40% of adults (up to 60% of men and 40% of women over 60 years), and in 3 to 12% of children. Prevalence increases with age, male sex, obesity, menopause and pregnancy (about 25 to 35% in late pregnancy).
• Types:
  • Primary (simple) snoring: no apnoeas, hypopnoeas, oxygen desaturation or daytime sleepiness. The apnoea hypopnoea index is below 5 events per hour.
  • Upper airway resistance syndrome: snoring with repeated arousals and daytime sleepiness without apnoea or desaturation.
  • Obstructive sleep apnoea: repeated collapse of the upper airway, with an apnoea hypopnoea index of 5 or more per hour with symptoms, or 15 or more per hour regardless of symptoms (mild 5 to 14, moderate 15 to 29, severe 30 or more). It affects about 10 to 15% of middle aged adults and is under diagnosed.
• Contributing factors: obesity (body mass index above 30, with neck circumference above 43 cm in men and 41 cm in women), alcohol and sedatives (relax pharyngeal muscles), supine sleep position, smoking, nasal obstruction (allergic rhinitis, a deviated septum, polyps, a cold), large tonsils and adenoids (the commonest cause in children), a long soft palate and uvula, a small or retruded jaw (retrognathia), a large tongue (acromegaly, hypothyroidism, Down syndrome), pregnancy, menopause, and certain drugs (benzodiazepines, opioids, muscle relaxants, antihistamines).
• Complications of snoring with OSA: daytime sleepiness, impaired concentration, accidents (road traffic), hypertension (resistant), atrial fibrillation, coronary disease, stroke, heart failure, type 2 diabetes, depression, nocturia, erectile dysfunction, gastro oesophageal reflux, and increased perioperative risk. Social effects on bed partners include poor sleep and relationship strain.
• In children, snoring with sleep disordered breathing (adenotonsillar hypertrophy) affects growth, behaviour (hyperactivity, inattention), school performance, enuresis, and cardiovascular health.

• Noisy breathing during sleep, reported by the bed partner or family, which may be continuous, positional (worse supine) or intermittent, and ranges from soft to disturbing loud noises. Snoring only when sleeping on the back and after alcohol favours simple snoring.
• Features of OSA: witnessed pauses in breathing, choking or gasping at night, restless sleep, nocturia (more than 1 to 2 times), morning headache, dry mouth, unrefreshing sleep, excessive daytime sleepiness (falling asleep when reading, watching television, in meetings or driving), irritability, poor concentration, memory loss, reduced libido and depression. Sweating and reflux at night may occur.
• Examination: weight, body mass index, neck circumference, blood pressure (often raised), the oropharynx (a crowded airway with a Mallampati class 3 or 4, a low lying soft palate, a long uvula, enlarged tonsils, a large tongue), jaw position (retrognathia), nasal passages (septal deviation, turbinate hypertrophy, polyps), and signs of hypothyroidism or acromegaly.
• Children: mouth breathing, snoring more than 3 nights a week, restless sleep, witnessed apnoea, sweating, enuresis, morning headaches, behaviour problems, hyperactivity, failure to thrive, and enlarged tonsils and adenoids (adenoid facies with an open mouth).
• Differential diagnosis: OSA, upper airway resistance syndrome, obesity hypoventilation syndrome, central sleep apnoea, nocturnal asthma or reflux, narcolepsy, restless legs syndrome and periodic limb movements, insomnia, depression, hypothyroidism, heart failure (Cheyne-Stokes breathing), and nasal disease.
• Red flags: witnessed apnoeas with daytime sleepiness while driving or in a safety critical job, resistant hypertension, atrial fibrillation, heart failure, stroke, type 2 diabetes with poor control, pulmonary hypertension, morbid obesity (body mass index above 35) with daytime hypercapnia, polycythaemia, new onset snoring with voice change, dysphagia or weight loss (tumour), a neck mass, stridor, and pregnancy with hypertension (pre-eclampsia).

• Clinical assessment with a validated questionnaire is the first step. Use a sleepiness score (for example, an 8-item scale scored 0 to 24, with a score above 10 indicating excessive sleepiness), and a screening questionnaire for OSA: snoring, tiredness, observed apnoea, high blood pressure, body mass index above 35, age above 50, neck circumference above 40 cm, and male sex (a score of 3 or more has high sensitivity for moderate to severe OSA, and 5 to 8 has a high probability of OSA).
• Sleep study (needed if symptoms or risk factors suggest OSA):
  • Home sleep apnoea test (type 3 portable monitor: airflow, respiratory effort, oxygen saturation, heart rate) for adults with a high pretest probability of moderate to severe OSA and no major comorbidity.
  • Attended in laboratory polysomnography when the diagnosis is uncertain, when comorbid cardiopulmonary, neuromuscular or sleep disorders are present, for children, and after a negative or technically poor home test. It records electroencephalogram, eye movements, muscle tone, airflow, effort, oxygen saturation, leg movements and body position.
  • Report the apnoea hypopnoea index (events per hour of sleep), the oxygen desaturation index and the lowest saturation.
• Simple overnight pulse oximetry is a low cost screening tool in some settings, but a normal result does not exclude OSA.
• Additional tests, as indicated: full blood count (polycythaemia), thyroid function tests (hypothyroidism), fasting glucose or HbA1c, lipid profile, serum bicarbonate and arterial blood gases (hypoventilation), echocardiography (pulmonary hypertension, heart failure), and electrocardiogram.
• ENT assessment with nasendoscopy (flexible fibreoptic examination of the nose, palate and pharynx), or drug induced sleep endoscopy, in selected patients when surgery is considered.
• Cephalometry or imaging for craniofacial abnormalities (retrognathia) in selected patients.
• Children: clinical assessment is first. A lateral neck X-ray (adenoid size) or nasendoscopy is used for adenoid hypertrophy, and polysomnography when there is doubt, comorbidity, or before surgery. An apnoea hypopnoea index of 1 or more per hour is abnormal in children, and above 5 is moderate to severe.
• Driving and occupation: assess the risk of drowsy driving, and advise patients with excessive sleepiness not to drive until the condition is controlled.

• Primary snoring and mild OSA (lifestyle first):
  • Weight loss: a loss of 10% of body weight reduces the apnoea hypopnoea index by about 25 to 50%, and body mass index should be reduced to below 25 where possible. Offer dietary and exercise support, pharmacotherapy (such as semaglutide 0.25 mg subcutaneously once weekly, increased monthly to 1 to 2.4 mg, or tirzepatide 2.5 mg weekly, increased every 4 weeks to 5 to 15 mg, for obesity in selected patients), or bariatric surgery when body mass index is 35 or more with comorbidity.
  • Avoid alcohol for at least 4 hours before bed (ideally 6 hours), avoid sedatives, benzodiazepines and opioids at night where possible, and stop smoking.
  • Positional therapy for supine dependent snoring: sleep on the side, using a tennis ball sewn into the back of a pyjama top, a wedge or positional pillow, or a vibrating positional device, with the head of the bed raised by 10 to 15 cm.
  • Treat nasal obstruction: saline irrigation, intranasal fluticasone propionate 50 micrograms per spray, 2 sprays into each nostril once daily for 4 to 8 weeks, intranasal decongestant for at most 3 to 5 days before bed, and nasal dilator strips or internal nasal dilators.
  • Regular sleep schedule of 7 to 9 hours, and treat reflux, allergic rhinitis and hypothyroidism where present.
• Oral appliance therapy: custom made mandibular advancement device (a dentist fitted device that moves the lower jaw forward 50 to 75% of maximum protrusion) for primary snoring, mild to moderate OSA, or CPAP intolerance. It reduces the apnoea hypopnoea index by about 50%, with adverse effects of jaw and tooth discomfort, excessive salivation or dry mouth, and bite changes after long term use. Dental review every 6 to 12 months. Tongue retaining devices are an alternative.
• Continuous positive airway pressure (CPAP) for moderate to severe OSA (apnoea hypopnoea index 15 or more), and for mild OSA with symptoms, cardiovascular disease or excessive sleepiness:
  • Fixed pressure 4 to 20 cm of water set after titration (auto titrating machines adjust 4 to 20 cm of water), with a nasal, nasal pillows or full face mask, humidification, and a ramp.
  • Aim for use more than 4 hours per night on at least 70% of nights, and ideally all night. Check adherence after 1 week, 1 month, and 3 months (download data from the machine), with problem solving for mask leaks, nasal dryness, claustrophobia, aerophagia, and pressure intolerance.
  • It reduces sleepiness, blood pressure (by 2 to 3 mmHg on average, more in resistant hypertension), road accident risk, and improves quality of life. Evidence for cardiovascular event reduction is mixed.
  • Bilevel positive airway pressure for obesity hypoventilation or when CPAP is not tolerated, in specialist care.
• Surgical and procedural options (specialist, selected patients):
  • Adenotonsillectomy in children with adenotonsillar hypertrophy (first line, with cure in 60 to 80%, lower in obese children), and in adults with large tonsils.
  • Nasal surgery (septoplasty, turbinate reduction, polypectomy) to improve nasal airflow and CPAP tolerance, which alone seldom cures OSA.
  • Palatal surgery (uvulopalatopharyngoplasty, and modified or less invasive palatal techniques, including palatal implants and radiofrequency reduction) for snoring or mild OSA with palatal obstruction. Success for OSA is about 40 to 50%, with persistent pain, swallowing problems and a nasal voice as risks.
  • Maxillomandibular advancement (cure rate above 80% in selected patients with moderate to severe OSA), and genioglossus advancement.
  • Hypoglossal nerve stimulation (an implanted device that stimulates the tongue muscle during sleep) for patients with moderate to severe OSA (apnoea hypopnoea index 15 to 65), who cannot tolerate CPAP, with body mass index below 32 to 35, and without complete concentric collapse on sleep endoscopy.
  • Bariatric surgery in severe obesity, and tracheostomy for life threatening OSA (rare).
• Children: adenotonsillectomy for sleep disordered breathing with enlarged tonsils and adenoids (apnoea hypopnoea index above 1 with symptoms). For mild disease, or when surgery is delayed or not possible, use intranasal mometasone furoate 50 micrograms per spray, 1 spray into each nostril once daily (age 3 to 11 years), or fluticasone furoate 27.5 micrograms per spray, 1 spray into each nostril once daily, for 6 to 12 weeks, and montelukast 4 mg (2 to 5 years) or 5 mg (6 to 14 years) orally once daily at night for 12 weeks. Treat allergic rhinitis and obesity, and arrange follow up polysomnography 6 to 12 weeks after surgery in those with severe disease, obesity, craniofacial anomalies, or persistent symptoms. CPAP is used when surgery is not curative or not possible.
• Medicines: avoid sedative hypnotics, benzodiazepines, opioids, and alcohol. Modafinil 100 to 200 mg orally in the morning, or armodafinil 150 to 250 mg, is used for residual sleepiness in patients adherent to CPAP and after exclusion of other causes (specialist care). Acetazolamide and oxygen therapy are limited to selected patients. There is no proven drug treatment for snoring alone.
• Over-the-counter anti-snoring sprays, throat sprays, and herbal remedies lack evidence of benefit. Nasal strips help only when nasal valve collapse contributes.
• Special groups:
  • Pregnancy: encourage side sleeping, treat nasal congestion with saline and intranasal steroids (budesonide), monitor blood pressure and fetal growth, and refer for sleep study if snoring is severe, witnessed apnoea occurs, or hypertension develops. CPAP is safe and used when OSA is confirmed.
  • Elderly: consider heart failure, stroke, and sedative use. CPAP and oral appliances are suitable, with the aim of treatment guided by symptoms and comorbidity.
  • Drivers and safety critical workers: inform them not to drive when sleepy, and arrange urgent sleep assessment. Return to driving once symptoms are controlled and adherence is shown.
  • Perioperative patients: tell the anaesthetist about suspected or known OSA, avoid high doses of opioids and sedatives, continue CPAP after surgery, and use monitoring.
  • Down syndrome, craniofacial anomalies and neuromuscular disease: high risk of OSA, and referral for early sleep study.
  • Hypothyroidism and acromegaly: treat the underlying disorder.
  • Obesity hypoventilation: refer to a sleep or respiratory specialist for bilevel pressure support and weight loss.
• Follow up: review at 4 to 12 weeks after starting treatment. For CPAP, review at 1 week, 1 month and 3 months, then annually, with symptom scores, adherence data, weight, blood pressure and mask fit. For oral appliances, dental review every 6 to 12 months and a repeat sleep study to confirm effect. Refer to a sleep physician or ENT surgeon when OSA is suspected, when initial measures fail, in children with symptoms, and in patients with comorbid cardiopulmonary disease, hypoventilation, or a safety critical occupation.