What is Sleep Apnoea? Sleep apnoea is a serious medical condition where the walls or muscles of the upper airway relax in such a way that inevitably blocks the airway during sleep. This results in an interruption of air supply to the lungs. It can last up to a minute or more, and may occur numerous times throughout the night. Your brain soon realises that there is a problem, and the body is not receiving any oxygen. The brain will “wake up” briefly and will shock the cardiova