Obstructive Sleep Apnoea is a breathing disorder which occurs during sleep. It is caused by the transient closure of the upper airways. People with Obstructive Sleep Apnoea stop breathing for at least 10 seconds at a time while they are sleeping (Apnoea). These short stops in breathing can happen hundreds of times every night. After practicaly every apnoea the brain briefly wakes the individual, which causes fragmented sleep. This fragmented sleep causes the most worrying sympton - excessive daytime sleepiness.

There are three kinds of sleep apnoea: obstructive apnoea, central apnoea and mixed apnoea. Obstructive Sleep Apnoea is the most common type. Nine out of 10 people with Sleep Apnoea have this type of apnoea. If you have Obstructive Sleep Apnoea, the passage or windpipe (called the trachea) that brings air into your body is obstructed. You keep trying to breathe, but you can't get enough air because of the obstruction. Your windpipe might be blocked by your tongue, tonsils or uvula (the little piece of flesh that hangs down in the back of your throat). It might also be blocked by a large amount of fatty tissue in the throat or even by relaxed throat muscles.