Obstructive sleep apnoea (OSA) is a relatively common condition – particularly among men aged 30-60 years old – where the walls of the throat relax and narrow during sleep, causing repeated interruption to the person’s breathing. As a result, oxygen levels in the blood fall, which triggers the brain to wake the person up, which may occur many times during the night. 

OSA most often occurs in people who are overweight or obese, or who have a large neck, narrow airway, small lower jaw or large tonsils, adenoids or tongue. Nasal polyps or a deviated septum in the nose also increase the risk of OSA, as do taking sedative medicines and smoking or drinking alcohol before sleep. There may also be a genetic element. 

The most common symptoms of OSA include snoring, noisy or laboured breathing, and repeated periods where breathing is interrupted by gasping or snorting. Sufferers may feel drowsy the following day, have poor memory or difficulty concentrating and be more prone to headaches, mood swings, irritability and depression.