As we go to sleep, the muscles of the throat relax as a normal part of the sleep process. In individuals with Obstructive Sleep Apnoea (OSA), this relaxation progresses to the point where the passage for air is partially or completely blocked, dramatically reducing or stopping airflow into the lungs.

This causes an increase in Carbon Dioxide levels and the brain responds by waking up the individual for a short while to open the air passage. Breathing begins again, but the natural sleep cycle is interrupted. Ingestion of alcohol, sleeping pills, anti-depressants or smoking increases the frequency and risk of breathing pauses in people with Obstructive Sleep Apnoea.

Consequences of untreated Obstructive Sleep Apnoea include Excessive sleepiness during the day, frequently "nodding off"; Impairment of cognitive function i.e. thinking, memory problems; Mood and personality changes; Reduction in quality of life; Heart Disease and possibly an increase in the risk of Stroke.