Definitions of obstructive sleep disordered breathing (SDB) and its clinical entities
| Definition | |
| Obstructive SDB | A syndrome of upper airway dysfunction during sleep characterised by snoring and/or increased respiratory effort that result from increased upper airway resistance and pharyngeal collapsibility |
| Clinical entities | |
| Primary snoring | Habitual snoring (>3 nights per week) without apnoeas, hypopnoeas, frequent arousals from sleep or gas exchange abnormalities |
| Upper airway resistance syndrome | Snoring, increased work of breathing, frequent arousals, but no recognisable obstructive events or gas exchange abnormalities |
| Obstructive hypoventilation | Snoring and abnormally elevated partial pressure of carbon dioxide in the absence of recognisable obstructive events |
| Obstructive sleep apnoea syndrome | Recurrent events of partial or complete upper airway obstruction (hypopnoeas, obstructive or mixed apnoeas) with disruption of normal oxygenation, ventilation and sleep pattern |
Information from [4, 5].