Obstructive sleep apnoea causes the throat walls to relax and narrow during sleep. This affects normal breathing patterns and causes symptoms such as snoring and heavy breathing.
Two ways that breathing is affected are:
- Apnoea – the muscles and soft tissue in the throat relax to the point where your airway is completely obstructed. Apnoea refers to a blocked airway for more than 10 seconds.
- Hypopnoea – this refers to a partial blockage of the airway, reducing airflow by 50% for 10 seconds or more.
If you suffer with OSA, you may experience both apnoea and hypopnoea through the night. Therefore, this condition is sometimes referred to as obstructive sleep apnoea-hypopnoea syndrome (OSAHS).
For severe cases, symptoms of either apnoea or hypopnoea may occur every couple of minutes, making sleep extremely disturbed.