Snoring and sleep apnoea

Obstructive sleep apnoea affects a large proportion of the adult population and the majority of cases remain undiagnosed, which is unusual for a condition with such clear consequences.

The mechanism

During sleep the muscles of the upper airway relax.

Snoring is the sound of turbulent airflow through a narrowed airway.

In obstructive sleep apnoea the airway narrows enough to substantially reduce airflow, or closes entirely, until oxygen levels fall and the brain produces a brief arousal to restore muscle tone.

This can occur dozens of times an hour, each time fragmenting sleep without the person waking properly or remembering it.

The result is unrefreshing sleep of normal duration, plus repeated drops in oxygen and surges in sympathetic activity through the night.

Who gets it

Risk rises with weight, and central adiposity and neck circumference are strong predictors, though a substantial number of people with apnoea are not overweight.

Male sex, though it is significantly underdiagnosed in women, partly because presentations differ — women more often report fatigue, insomnia and mood symptoms rather than classic snoring and witnessed apnoeas.

Age.

Craniofacial structure, including a small or set-back jaw, which explains cases in slim people.

Large tonsils, which is the dominant cause in children.

Menopause, after which risk in women rises considerably.

Alcohol and sedatives, which worsen it.

And nasal obstruction, which contributes.

The consequences

Why it matters beyond feeling tired.

Excessive daytime sleepiness, with a well-documented increase in road traffic accident risk that has licensing implications in most countries.

Hypertension, particularly hypertension resistant to treatment, where apnoea is a recognised secondary cause.

Associations with atrial fibrillation, stroke, cardiovascular events and type 2 diabetes.

Impaired concentration and memory.

Low mood.

Nocturia, which is frequently attributed to the prostate.

And the effect on a bed partner, whose own sleep is frequently the reason the problem is finally raised.

The signs

Loud habitual snoring, particularly with witnessed pauses or gasping.

Waking unrefreshed regardless of duration.

Morning headaches and a dry mouth.

Falling asleep unintentionally during the day.

Waking suddenly with a choking sensation.

And in children: snoring, mouth breathing, restless sleep, and behavioural or attention problems rather than sleepiness.

Diagnosis

Screening questionnaires are used to decide who needs testing.

Home sleep tests, measuring oxygen saturation, airflow and effort, are now the standard route in many systems and are considerably more accessible than an overnight laboratory study.

Laboratory polysomnography remains necessary where the picture is complicated or other sleep disorders are suspected.

Severity is graded by the number of events per hour, which combined with symptoms determines treatment.

Treatment

Continuous positive airway pressure is the most effective treatment for moderate to severe disease, holding the airway open with pressurised air.

It works, and adherence is the limiting factor: mask fit, pressure settings, humidification and support all substantially affect whether people continue, and the difficulty is common enough that persistent problems should trigger a review rather than abandonment.

Mandibular advancement devices, made by a dentist with expertise, hold the jaw forward and are effective for mild to moderate disease and for those who cannot tolerate positive pressure.

Weight loss produces meaningful improvement and in some cases resolution, and newer pharmacological options for weight have shown effects on apnoea severity in trials.

Positional therapy where events occur mainly on the back.

Surgery in selected cases, particularly tonsillectomy in children, which is curative in most.

And avoiding alcohol and sedatives in the evening, which is straightforward and effective.

Snoring without apnoea

Still worth addressing for the sake of the household.

Weight, alcohol timing, sleeping position, nasal congestion and allergy treatment all help.

Devices sold for snoring vary from reasonable to useless, and the ones with evidence are the mandibular devices fitted properly rather than the boil-and-bite versions.

And a bed partner sleeping elsewhere is a reasonable interim arrangement rather than a defeat.

General information only, not medical advice. Consult a qualified clinician if you snore with pauses in breathing or experience daytime sleepiness, particularly if you drive.