Continuous Positive Airway Pressure (CPAP - pronounced "Cee-pap"). A CPAP device is essentially a pump that delivers air at an increased pressure. The basic form of this treatment is fixed CPAP therapy which delivers a fixed or constant pressure all night long. An alternative treatment is Automatic Positive Air­way Pressure (APAP) which adjusts the pressure throughout the night to changes in the sufferer's airway. The third alternative is Bi-Level therapy (BiPAP) which provides a lower pressure when exhaling, but a higher pressure when inhaling. It is considered a more comfortable option for the CPAP user, especially those on higher pressures.

In Obstructive Sleep Apnoea (OSA) the upper part of the air passage behind the tongue narrows and collapses during sleep causing an interruption to breathing. Snoring occurs when the air passage is narrowed and air flowing through the narrow passage causes it to vibrate. Since in both snoring and OSA the interruptions to sleep are caused by either narrowing or complete collapse of the air passage, treatment is designed to stop the air passage from narrowing during sleep. The flow of air from the CPAP therapy creates a 'splint' to keep the airway open. Once the air passage is held open, breathing is completely normal and there are no interruptions to sleep.