Snoring and Obstructive Sleep Apnoea
On this page
Direct answer
Snoring becomes disease when upper airway collapse during sleep produces repetitive apnoeas and hypopnoeas: obstructive sleep apnoea (OSA) is defined as an apnoea-hypopnoea index (AHI) of five or more events per hour with symptoms such as daytime sleepiness, loud snoring and witnessed apnoeas, graded as mild (AHI 5-15), moderate (15-30) and severe (over 30). Diagnosis rests on polysomnography — the gold standard, level 1 study — with home sleep apnoea testing acceptable for high-probability uncomplicated patients, and STOP-BANG (snoring, tiredness, observed apnoea, pressure, BMI, age, neck circumference, gender) as the practical screening tool scoring high risk at three or more. Continuous positive airway pressure (CPAP) is first-line treatment for moderate-to-severe disease, with weight loss, mandibular advancement devices for mild-moderate cases, and surgery (adenotonsillectomy in children, selected palate or skeletal procedures in adults) in defined situations.
What you must remember
- Severity ladder: AHI 5-15 mild, 15-30 moderate, more than 30 severe; the AHI plus oxygen desaturation index and symptoms together drive treatment decisions.
- Screening tool: STOP-BANG questionnaire — snoring, tiredness, observed apnoea, pressure, BMI over 35, age over 50, neck over 40 centimetres and male gender — 3 or more flags high risk.
- Gold standard investigation: attended polysomnography (level 1) with electroencephalography, airflow, respiratory effort, oximetry and electromyography; level 3 home studies (cardiorespiratory, no sleep staging) suit straightforward high-probability cases without significant comorbidity.
- Clinical markers: daytime somnolence, morning headache, unrefreshing sleep and nocturia; consequences include systemic and pulmonary hypertension, arrhythmia, insulin resistance and road accidents.
- CPAP: first-line for moderate-to-severe OSA — a pneumatic splint of the collapsible pharynx; adherence is the weak link, and humidification, mask fitting and follow-up determine success.
- Surgical map by level: nose (septal and turbinate surgery as adjunct, rarely curative alone), palate and oropharynx (uvulopalatopharyngoplasty — UPPP, best for palate-level obstruction in Friedman stage I-II), tongue base (advancement, radiofrequency), and skeleton (maxillomandibular advancement, the most efficacious airway-enlarging procedure); bariatric surgery for the morbidly obese.
- Paediatric difference: adenotonsillar hypertrophy is the commonest cause and adenotonsillectomy the first-line treatment in children — contrast with CPAP-first adults; residual paediatric OSA is often obesity-related.
- Indian angle: Indian guidelines commonly apply lower body-mass-index cutoffs for obesity in Asians (23 and 25 kg per m2 for overweight and obesity in several national documents), and OSA occurs in relatively non-obese Indians with craniofacial patterns such as a retrognathic mandible — screen on symptoms and neck, not BMI alone.
Worked example: from symptom score to pressure setting
A 46-year-old businessman is referred for loud snoring, witnessed choking and dozing at the wheel. His body mass index is 29 — obese by Asian Indian criteria — neck circumference 42 centimetres, blood pressure 150/95, and STOP-BANG computes six. Polysomnography shows an apnoea-hypopnoea index of 34 with desaturations to 82 per cent: severe disease. The consultation that follows is the treatment — explain the pneumatic splint logic of continuous positive airway pressure, titrate during a second study or with an auto-titrating device, and refit the mask at two weeks, because the first mask leaks, the commonest cause of abandonment. Weight loss of even 10 per cent meaningfully lowers the index, so diet and follow-up are part of the prescription.
Change the patient and the ladder changes. A mildly overweight 29-year-old woman with retrognathia and an index of 11 gets a mandibular advancement device, with septoplasty for concurrent nasal blockage as an adjunct. A six-year-old with big tonsils, snoring and bed-wetting gets adenotonsillectomy, with pressure therapy only for residual disease. One physiology, three ladders, selected by age, severity and anatomy.
Where students slip
Candidates treat polysomnography as optional in moderate-to-severe disease or demand a level 1 study for every snorer — screening identifies risk, objective testing grades it, and home testing suits the right patient. Uvulopalatopharyngoplasty is chosen as the default surgical answer, though it benefits selected palate-level obstruction and does not reliably cure severe or tongue-level disease. Nocturia and morning headache are forgotten as presenting symptoms, and the paediatric answer — adenotonsillectomy first — is reversed to adult logic.
Frequently asked questions
How is obstructive sleep apnoea severity graded by AHI?
Mild corresponds to an apnoea-hypopnoea index of 5-15 events per hour, moderate 15-30, and severe above 30, interpreted alongside oxygen desaturation and daytime symptoms.
What is the gold standard investigation for OSA?
Attended overnight polysomnography (a level 1 study) recording sleep staging, airflow, respiratory effort and oxygenation; home sleep apnoea testing is an acceptable alternative in uncomplicated high-probability patients.
What does the STOP-BANG questionnaire score?
Eight items — snoring, tiredness, observed apnoea, pressure/hypertension, BMI over 35, age over 50, neck circumference over 40 cm and male gender — with 3 or more indicating high risk.
What is the first-line treatment for moderate-to-severe OSA in adults?
Continuous positive airway pressure, which pneumatically splints the pharynx, supported by weight loss; adherence follow-up determines success.
Which surgery is first-line for a child with obstructive sleep apnoea?
Adenotonsillectomy, because adenotonsillar hypertrophy is the commonest cause in children — unlike adults, where CPAP leads the algorithm.