‘Laugh and the world laughs with you, snore, and you snore alone’ — from Anthony Burgess's Inside Mr Enderby (1963). It is a misquote of the original ‘Laugh and the world laughs with you, weep, and you weep alone’, from Ella Wheeler Wilcox (1855-1919).
Snoring has been a source of material for music hall mirth and general humour for centuries. Its association with obesity and alcohol has offered further scope for the stand-up comedian. Until relatively recently snoring was not considered a significant problem, except by the long-suffering partner behind closed bedroom doors, and those musing on the possible evolutionary advantage of snoring — the most entertaining suggestion from the latter being that snoring is a signal during the dark hours to potential marauders that there are large men about, so attack at your peril!
All this has changed since about 1965, when it was first reported that the pharynx, more specifically the airway behind the tongue, could collapse repeatedly during sleep, thus recurrently asphyxiating the sufferer, over and over again, hundreds of times a night. This condition is generally called obstructive sleep apnoea. This incompetence of the pharynx and failure to remain adequately patent only occurs during sleep, when muscle tone is at its lowest. It is always accompanied by loud snoring, which develops when the pharyngeal walls are close enough together to vibrate, a half-way house to complete obstruction. This condition of obstructive sleep apnoea is not just a physiological curiosity, but has been shown to lead to profound sleep fragmentation and excessive sleepiness. More recently, this excessive sleepiness has been shown to increase substantially the risk of driving accidents.
Both snoring and sleep apnoea are common; about a quarter of men snore regularly and about 1% have sleep apnoea sufficient to cause some degree of excessive daytime sleepiness. Why should this be the case? To some extent the pharynx represents an area of ‘compromise engineering’. Because we must both eat and breathe through the pharynx, sometimes it has to be held open by muscles to allow air to pass unheeded, and sometimes it must collapse and propel food on its way into the oesophagus (gullet). Thus it is essentially a floppy tube, which requires muscle action to hold it open when required for breathing. The main factor that encourages narrowing and collapse is obesity, which crowds the pharyngeal airway and can overwhelm the dilator muscle action during sleep. For example, collar size is one of the best predictors of whether someone snores. In addition, if the pharynx is small to start with — for example if the lower face is relatively set back — or occupied by large tonsils, then it takes little further narrowing to obstruct airflow. It would have been so much better if nature had provided us with separate routes through which to eat and breathe!
Other factors that encourage snoring and sleep apnoea are the muscle relaxation brought about by alcohol, and a blocked nose (which encourages further collapse of the pharynx during inspiration).
What does all this mean to the health of the human body? There is little evidence that occasional light snoring does any harm at all. As the amount of obstruction in the pharynx gets more, and the snoring gets louder, then this indicates a compromised airway and increasingly obstructed breathing. This in turn produces poor, fragmented sleep and daytime sleepiness. Thus a snorer with daytime sleepiness should be encouraged to seek help. There is also increasing evidence that heavy snoring and sleep apnoea may contribute to a raised blood pressure, with secondary consequences such as stroke and heart attacks. However, this effect is likely to be small when compared with other known risk factors such as smoking.
The sound of snoring alone causes much misery to partners, and for this reason many remedies are peddled. Few have robust scientific support, although weight loss, alcohol reduction, and sleeping semi-propped up are usually the simplest first approaches. Small intra-oral devices worn in the mouth at night to hold the lower jaw forward are increasingly popular. Surgery should be viewed as a last resort for the desperate, as it is of only limited efficacy. At the more severe end of the spectrum, for obstructive sleep apnoea, nasal continuous positive airway pressure treatment is highly effective. This requires wearing, during sleep, a mask over the nose that gently pressurizes the upper airway and splints it open, preventing the narrowing and collapse. However, this is difficult to get used to, and is only tolerated by individuals suffering from incapacitating daytime sleepiness — which this treatment abolishes, leading to spectacular improvement in quality of life.
— J. Stradling
See also sleep; sleep disorders.
The Oxford Companion to the Body. Copyright © 2001, 2003 by Oxford University Press. All rights reserved.
