About 12% of chronic snorers have a potentially serious medical disorder called obstructive sleep apnoea.

Many obstructive sleep apnoea sufferers are not aware they have a problem. It affects 4% of the adult population. Sleep apnoea leads to excessive daytime sleepiness, lack of concentration and poor memory. Over time, it may cause serious damage to the heart and brain. 

During sleep all of your muscles relax, including those surrounding the airway. In simple snoring, the narrowed airway vibrates but does not block off. Obstructive sleep apnoea is caused by the tongue and other soft tissues in the back of the throat falling backwards and blocking the airway.

Some people are particularly at risk of this, because the airway is narrow from obesity or the lower jaw is relatively small. It is made worse by alcohol or sedatives that cause extra muscle relaxation.

Obstructive sleep apnea can appear at all ages, most frequently in men between the ages of 30 to 60 and in women after the menopause.