Over the past four decades, obstructive sleep apnoea (OSA) has emerged as a prevalent, clinically important disorder. Snoring, which is often a hallmark of OSA, is seemingly ubiquitous in middle-aged men. Over 80% of Australian middle-aged men snore for more than 10% of the night.1 Snoring is also common in women. Although it is undoubtedly an important social nuisance, it remains unclear whether snoring alone (in the absence of sleep apnoea) carries with it any serious health risk. Twenty-five per cent of middle-aged men and 10% of women have OSA, defined as > 5 obstructed breathing events per hour of sleep.2 The prevalence in women rises sharply after menopause. Other risk factors are obesity, older age and a family history of OSA. Population-based studies in China and India indicate that its prevalence is at least as high as that reported in Western countries. A complex interplay between regulation of breathing during sleep, facial anatomy and obesity predicts the development of OSA.2 In contrast to the uncertainty of the effects of simple snoring, OSA clearly has significant health consequences.