SNORING AND SLEEP APNOEA
Snoring and the disturbance it causes used to be regarded as a joke, about
which little could be done. However we now know that snoring can indicate that
there are problems with breathing at night which may harm the snorer. Also
there are things that can be done to help alleviate snoring.
During sleep all the body's muscles become less active and more floppy. In
most parts of the body this does not matter and indeed helps one to relax and
sleep comfortably. However, when the muscles that help hold open the throat
behind the tongue relax, this leads to partial collapse and narrowing in this
area. Even in normal people this increases the resistance to the flow of air
when breathing in, but this is usually of no significance.
When this narrowing is more than normal, then the airway behind the tongue
collapses much more. Initially, this causes snoring and then, when the collapse
is complete, it causes apnoea, which means "without breath" - actual
stopping breathing. Fortunately, the body is able to sense this increased
obstruction to breathing, and the sufferer wakes briefly, before suffocation
can occur, takes a few deep breaths, and rapidly returns to sleep.
This obstruction and waking often becomes a continuous cycle, every minute
or so, that can go on hundreds of times each night. Usually, though, the
individual does not remember all these episodes of waking.
Causes
The things that cause sleep apnoea do so by increasing the normal narrowing
of the throat during sleep.
Anything that makes the throat narrower to start with (for example, enlarged
tonsils or a set back lower jaw) means that it is easy for the throat to close
off a bit more and block the airway. A partially blocked nose causes lower
pressures in the throat whilst taking a breath in, which tends to suck the
walls of the throat together.
Probably the most important factor is being overweight, with a large neck.
Extra fat in the neck squashes the throat from outside, particularly when the
throat muscles become floppier with sleep.
Incidence
The sort of person who most commonly suffers from heavy snoring and sleep
apnoea is an overweight middle-aged man with a large neck, usually taking a
size 17-inch collar or more. However, there are many people with sleep apnoea
who are not particularly overweight, and in some the reason why they have sleep
apnoea is not understood.
In children, the commonest cause is enlarged tonsils. Nowadays sleep apnoea
is a common reason for recommending that a young child has a tonsillectomy.
Sleep apnoea and heavy snoring, severe enough to interfere with sleep
quality, is probably much more common than is realised. At least three in every
thousand men have severe sleep apnoea.
Symptoms
Because sleep can be so disrupted by the body having to wake up briefly to
reverse the upper airway obstruction, sufferers experience severe daytime
sleepiness. To start with, this occurs only during potentially boring
activities such as reading, watching television, or driving on motorways.
However when the sleepiness gets worse, it begins to interfere with most
activities, with sufferers falling asleep talking or eating. Poor work
performance can lose the sufferer his or her job, and of course sleepiness
whilst driving can be fatal (sleep apnoea sufferers are about seven times more
likely to have car accidents). Snoring will usually have been present for many
years, and have gone well beyond a joke within the family.
There are many other symptoms, as one might expect in someone who is
seriously sleep deprived (irritability, for example), but the twin symptoms of
snoring and daytime sleepiness are the best pointers to the diagnosis.
Diagnosis
The presence of significant sleep apnoea may be strongly suspected from the
symptoms. Often the individual's partner has read an article about sleep apnoea
and recognises that this must be what their partner has. Once sleep apnoea is
suspected, then a sleep study is done to confirm the diagnosis. A hospital
referral to a lung specialist is necessary for this.
A variety of measurements can be made during a sleep study without
discomfort. Oxygen levels in the blood can be continuously measured from a clip
on the finger, and breathing monitored from belts around the chest and tummy.
Sleep quality itself can be estimated from wires stuck to the scalp, or from
the number of body movements made during sleep.
Video recordings with sound are often used, so that the doctor can actually
see how badly the breathing is obstructed and the sleep disturbed. Although
such sleep studies usually involve a night's stay in hospital, the British Lung
Foundation is funding research to develop reliable tests that can be done in
the person's own home.
Treatment
When sleep apnoea and snoring are not severe, then simple approaches can
help. Losing some weight, not drinking alcohol after 6.00 p.m. (alcohol relaxes
the upper airway muscles even more), keeping the nose as clear as possible, and
sleeping on one's side or semi-propped up can all help.
When snoring is very objectionable, with the individual and his or her
partner desperate for a solution, then an operation on the back of the throat
may help. However, this is a last resort and should only be done when a sleep
study has shown snoring alone with very little, or no, sleep apnoea.
The only really effective treatment currently used for bad sleep apnoea is
nasal continuous positive airway pressure (nasal CPAP). Because the inside of
the throat is narrowing, it can be held open by slightly pressurised air.
To deliver this air, a mask is worn during sleep just over the nose and
connected to a small, quiet pump beside the bed. Breathing is then able to
return to normal during sleep, with the air gently blowing through the nose,
holding open the throat. The response is usually dramatic, with greatly
improved sleep and disappearance of the day-time sleepiness.
Although these devices are cumbersome to wear, and hardly improve one's
appearance, the benefits far outweigh the disadvantages, with the vast majority
of people deciding to use their machines every night at home after a one night
trial in hospital.
For further information, contact:
British Lung Foundation
8 Peterborough Mews
London
SW6 3BL
 020-7371 7704
(Birmingham): 0121-236 8611 (ext 5985)
(Bristol): 01272 594959
(Glasgow): 0141-204 4110
(Liverpool): 0151-228 4723
(Newcastle): 0191-263 0276
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