When Sleep Breaks Down
Common sleep disorders — insomnia, apnoea, and circadian disorders
Everything so far assumes a sleep system that's fundamentally working, just poorly scheduled or poorly supported. For a substantial share of people, the problem is a genuine sleep disorder — common, frequently undiagnosed, and in most cases highly treatable once identified. This section is deliberately brief and practical: recognise the pattern, then see a clinician.
Chronic Insomnia
Clinically defined as persistent difficulty falling asleep, staying asleep, or waking too early, occurring at least three nights a week for three months or more, with meaningful daytime impact. The European Sleep Research Society's clinical guideline, based on a systematic review of the meta-analytic evidence, recommends cognitive behavioural therapy for insomnia (CBT-I) as the first-line treatment for chronic insomnia in adults of any age, ahead of medication[14]. A meta-analysis of 20 randomised controlled trials found CBT-I produces clinically meaningful improvements in sleep that are well sustained over time[15] — see Section 11 for what CBT-I actually involves.
Obstructive Sleep Apnoea
A literature-based modelling analysis estimated that close to 1 billion adults worldwide have obstructive sleep apnoea of at least mild severity, with roughly 425 million experiencing moderate-to-severe disease — the large majority undiagnosed[16]. OSA involves repeated pauses or reductions in breathing during sleep as the airway partially or fully collapses, fragmenting sleep without the person necessarily waking enough to remember it.
Common signs: loud or irregular snoring, gasping or choking sounds during sleep (often reported by a partner), waking unrefreshed regardless of hours slept, morning headaches, waking to urinate during the night, and significant daytime sleepiness.
Why it matters beyond tiredness: untreated OSA is associated with elevated cardiovascular, metabolic, and cognitive risk, largely through repeated drops in blood oxygen and fragmented sleep architecture.
Treatment is effective: CPAP (continuous positive airway pressure) and oral appliances are both well-established, effective treatments once diagnosed via a sleep study — a home sleep test is often a reasonably accessible first step if these signs sound familiar.
Delayed Sleep Phase Disorder
Distinct from simply being a night owl by preference: DSPD is a circadian rhythm disorder in which the internal clock is persistently shifted later, making it genuinely difficult to fall asleep before the early hours of the morning and equally difficult to wake at a conventional time, even with consistent effort. A specific gene variant (CRY1) identified in some familial cases lengthens the circadian period and is associated with a 2–2.5 hour delay in sleep timing[9] — a reminder that for some people, this pattern has a biological basis rather than being purely behavioural. It typically responds to structured morning light therapy and, under clinical guidance, carefully timed low-dose melatonin — not simply "trying harder" to sleep earlier.
Restless Legs Syndrome
An uncomfortable, often hard-to-describe urge to move the legs, typically worse in the evening and at rest, which can significantly delay sleep onset. It's associated in some cases with iron deficiency, making a ferritin blood test a reasonable starting point for a doctor to check alongside other causes.
| Pattern | What it might indicate | Next step |
|---|---|---|
| Trouble falling/staying asleep, 3+ nights/week, for 3+ months | Chronic insomnia | Ask your doctor about CBT-I before medication |
| Loud snoring + witnessed pauses in breathing + morning headaches | Possible obstructive sleep apnoea | Ask about a sleep study or home sleep test |
| Can't fall asleep before 2–3am despite consistent effort, for months | Possible delayed sleep phase disorder | See a sleep specialist about light therapy and timed melatonin |
| Uncomfortable urge to move legs, worse at night | Possible restless legs syndrome | Ask your doctor about an iron/ferritin check |
This is not a diagnostic tool
This section can only tell you what's common enough to be worth a conversation. It cannot diagnose you. If any of the patterns above sound familiar and have persisted for more than a few weeks despite genuinely applying the fundamentals in this guide, the next step is a doctor or a sleep specialist — not another habit change.