Sleep disorders explained: apnoea, insomnia, restless legs and more.

"Bad sleep" covers a wide range of very different problems. Distinguishing between them matters, because the treatments have almost nothing in common.

Sleep-disordered breathing

Obstructive sleep apnoea is the most common medical sleep disorder in adults. The upper airway repeatedly narrows or closes during sleep, breathing is reduced or briefly stops, and sleep is fragmented by short arousals you usually do not remember. Typical clues are loud snoring, witnessed pauses, gasping, morning headaches, unrefreshing sleep and daytime sleepiness. It is diagnosed by recording breathing overnight, and it is linked to high blood pressure, heart disease and stroke when untreated.

Insomnia

Insomnia is difficulty falling asleep, staying asleep or returning to sleep, with daytime consequences, despite adequate opportunity to sleep. When it becomes chronic, the recommended first-line treatment is cognitive behavioural therapy for insomnia (CBT-I) rather than medication. Insomnia and sleep apnoea often coexist, which is why persistent insomnia with snoring deserves a test.

Restless legs syndrome and limb movements

An uncomfortable urge to move the legs, worse in the evening and relieved by movement, points to restless legs syndrome. Related periodic limb movements can disturb sleep without waking you fully. Iron status and certain medications are relevant, so this is worth raising with your GP.

Circadian rhythm problems

Here the sleep itself is normal but mistimed — delayed sleep phase in younger adults, advanced phase with age, and shift-work disorder. Treatment centres on timed light exposure and a consistent schedule rather than sedatives.

Parasomnias and excessive sleepiness

Sleepwalking, night terrors, teeth grinding and acting out dreams fall under parasomnias. Narcolepsy — overwhelming daytime sleepiness, sometimes with sudden loss of muscle tone — is uncommon but important, and needs specialist assessment.

Where to start

If your main problem is snoring, witnessed pauses in breathing or unexplained daytime sleepiness, testing your breathing overnight is the most direct next step. A home sleep test can be completed in one night in your own bed, with clinician review and a call explaining the result. If your main problem is lying awake with a settled mind and quiet breathing, structured insomnia treatment is more likely to help.