Sleep, and what it costs to get it wrong

Sleep is the one health behaviour where a large industry sells products and the treatment with the best evidence involves no purchase at all.

What insufficient sleep does

Experimental restriction studies show measurable effects within days.

Impaired glucose tolerance and insulin sensitivity.

Altered appetite hormones with increased intake, particularly of energy-dense food.

Reduced antibody response to vaccination.

Impaired attention, working memory, reaction time and emotional regulation, with performance decrements on some measures comparable to alcohol intoxication.

Increased injury risk in athletes, where studies of sleep duration and injury show a consistent relationship.

And increased road accident risk, which is a documented and substantial contributor to collisions.

Longer-term, cohort studies associate short sleep with cardiovascular disease, obesity and type 2 diabetes, with confounding difficult to eliminate.

How much is needed

Consensus recommendations for adults sit at around seven to nine hours, with individual requirements distributed around that.

A small minority genuinely need less.

Regularity of timing has emerged as an independent predictor in cohort research, in some analyses more strongly than duration — which means a consistent schedule matters as much as total hours.

The practical test of adequacy is waking reasonably restored and functioning without excessive sleepiness on days when nothing is imposed.

Insomnia and what treats it

The important clinical point.

Chronic insomnia is difficulty falling or staying asleep, several nights a week, for three months or more, with daytime consequences.

Cognitive behavioural therapy for insomnia is recommended as first-line treatment ahead of medication in major guidelines.

Its components include sleep restriction, stimulus control, cognitive work on beliefs about sleep, and relaxation techniques — several of which are the opposite of what exhausted people naturally do.

Sleep hygiene advice alone is not an effective treatment for chronic insomnia, which is why being handed the leaflet repeatedly is so unhelpful.

Digital and group delivery of the full programme is available in many places at low cost, and self-help versions based on the same principles have reasonable evidence.

Medication

Where the role is narrower than the prescribing.

Hypnotics have a place for short-term use in acute situations.

Longer use carries tolerance, dependence, rebound insomnia on withdrawal, and in older adults falls and cognitive effects.

Melatonin has a specific role in circadian rhythm disorders and in certain populations rather than as a general sedative, with regulatory status varying by country.

Over-the-counter sedating antihistamines are widely used, have anticholinergic effects and are generally not recommended for ongoing use.

Alcohol is the most widely used sleep aid and one of the worst, shortening sleep onset and fragmenting the second half of the night.

Sleep apnoea

The condition with the largest economic consequences and the largest undiagnosed population.

Obstructive sleep apnoea affects a substantial proportion of adults and the majority remain undiagnosed.

Signs: habitual loud snoring with witnessed pauses or gasping, waking unrefreshed, morning headaches, and excessive daytime sleepiness.

Consequences include hypertension, particularly treatment-resistant hypertension, and associations with atrial fibrillation, stroke and diabetes — plus a well-documented increase in road accident risk with licensing implications in most countries.

Home sleep testing is now the standard route in many systems and is considerably more accessible than an overnight laboratory study.

Treatment with positive airway pressure is highly effective when tolerated, and adherence is the limiting factor.

Sleep trackers

Useful for one thing.

Consumer wearables estimate total sleep and timing reasonably and estimate sleep stages poorly, since none measure brain activity.

They systematically overestimate sleep in people with insomnia, who lie still while awake.

Orthosomnia — sleep problems generated or worsened by preoccupation with tracker scores — is a described phenomenon.

The useful output is timing consistency across weeks; the stage breakdown and composite score are not clinical measures.

The economic case

Worth stating for organisations.

Analyses of the economic cost of insufficient sleep in several countries have produced very large figures, driven by productivity loss, absence, accidents and healthcare costs.

Presenteeism from fatigue costs more than absence in most estimates.

Which makes cultures that treat short sleep as commitment an expensive proposition, and makes shift pattern design a genuine organisational health and safety issue rather than a scheduling convenience.

General information only, not medical advice. Consult a qualified clinician about persistent sleep problems, and seek assessment if you snore with pauses in breathing or fall asleep during the day.