Glossary

Plain definitions, alphabetically.

AHI (Apnea-Hypopnea Index). The number of apneas and hypopneas per hour of sleep. 5–15 is mild, 15–30 moderate, 30 and above severe. Home tests calculate it against total recording time rather than sleep time, so they underestimate. How testing works

Apnea. A complete cessation of airflow, lasting ten seconds or more.

Bruxism. Grinding or clenching the teeth during sleep. Associated with disordered breathing. The interaction

Continuous positive airway pressure (CPAP). The standard treatment for obstructive sleep apnea — pressurised air splinting the airway open. Getting used to it

Cottle manoeuvre. The clinical version of the cheek-pull test: drawing the cheek outward to see whether it eases nasal breathing, which indicates nasal valve involvement. More

Deviated septum. The wall between the nasal passages bending to one side. Close to universal in mild form; only sometimes obstructive. When it matters

DISE (drug-induced sleep endoscopy). Examining the airway with a camera while the patient is sedated, to see where and how it collapses. Used before palatal surgery and before hypoglossal nerve stimulation. Why it matters

Hypopnea. A partial reduction in airflow with an associated oxygen drop or arousal. Counts toward the AHI alongside apneas.

Hypoglossal nerve stimulation. An implanted device that moves the tongue forward with each breath, for diagnosed moderate-to-severe apnea in people who cannot tolerate CPAP. Who qualifies

Intermittent hypoxia. The repeated fall and recovery of blood oxygen across apnea events. The mechanism behind most of untreated apnea's cardiovascular consequences. What it does

ISO 10993. The medical-device biocompatibility standard. Part 5 covers cytotoxicity, part 10 covers skin sensitisation and irritation. Check whether a claim refers to the adhesive alone or the finished product. How to read it

Mandibular advancement device (MAD). An oral appliance holding the lower jaw forward, pulling the tongue base away from the throat. The best-evidenced purchasable snoring remedy. Compared

Micro-arousal. A brief shift toward lighter sleep, usually not remembered, that interrupts sleep consolidation. The reason fragmented sleep leaves you unrefreshed despite adequate hours.

Nasal cycle. The normal alternation of congestion between nostrils every few hours. Physiology, not pathology. The explanation

Nasal valve. The narrowest point of the nasal airway, about a centimetre inside the nostril. The only part of the nose an external strip can reach. Valve collapse

Nitric oxide. A signalling molecule produced continuously by the paranasal sinuses and delivered to the lungs only during nasal breathing. What it does

Obstructive sleep apnea (OSA). Repeated closure of the pharyngeal airway during sleep. Distinct from snoring, which is narrowing rather than closure. The difference

Oropharyngeal exercises. Tongue and throat exercises that tone the tissue involved in palatal snoring. Roughly three months to show an effect. The exercises

PFAS. Per- and polyfluoroalkyl substances, persistent fluorinated compounds found in some adhesives and coatings. A credible "PFAS-free" claim names the compound count, the method and the standard. What to ask

Polysomnography. A full in-lab sleep study, recording brain activity, eye movement and muscle tone alongside airflow and oxygen. Required where a home test is inappropriate. When

Positional therapy. Preventing back sleeping, usually with a vibration trainer or a tennis ball. Free or cheap, and effective for the large group whose snoring is position-dependent. How

Primary snoring. Snoring without sleep apnea. What most snorers have. More

Rhinitis medicamentosa. Rebound congestion caused by overusing medicated decongestant sprays beyond a few days. Nasal strips have no equivalent. The distinction

Septoplasty. Surgery to straighten a deviated septum. Improves nasal breathing far more reliably than it eliminates snoring. The detail

Soft palate. The muscular back portion of the roof of the mouth. The tissue producing the classic fluttering snore.

Spousal arousal syndrome. The fragmented sleep experienced by the bed partner of a snorer. What it costs

Turbinates. Scrolled structures along the side walls of the nasal cavity that warm and humidify air. They swell with allergy and infection, sitting behind the nasal valve where a strip cannot reach.

UPPP (uvulopalatopharyngoplasty). Surgery reshaping the soft palate and uvula. Painful, with inconsistent results unless patients are carefully selected. The operations compared