When I see a child in clinic who has been referred for snoring, I am often also hearing a story that started somewhere else entirely: at school, in a paediatrician's office where ADHD was discussed, in a conversation about learning support, or in a GP surgery where a parent was told their child was simply an anxious or difficult child. Sleep apnoea in children is one of the most commonly missed diagnoses behind these presentations, and the consequences of missing it extend well beyond disrupted sleep.
Sleep apnoea in children is most commonly caused by enlarged tonsils and adenoids — the lymphoid tissue at the back of the throat and high in the nasal passage — which in young children can be large enough relative to the size of the airway to cause significant obstruction during sleep. Obesity is also a risk factor, particularly in older children. OSA affects between 1 and 5 per cent of all children, and sleep-disordered breathing in a broader sense (including partial obstruction and snoring without complete apnoea) is considerably more prevalent.
Behavioural Consequences: ADHD or Airway Problem?
This is the area where I think the clinical misdiagnosis rate is highest and the consequences of missing the diagnosis most significant. Children with untreated sleep apnoea display, on standardised behavioural rating scales, profiles of hyperactivity, inattention, and impulsivity that are neurologically indistinguishable from those of children with primary ADHD. They behave as if they are struggling to regulate their attention and activity level — because they are. They are struggling because their brains are sleep-deprived and hypoxic, not because of the neurodevelopmental differences that characterise ADHD.
Children — unlike adults — do not respond to sleep deprivation by becoming drowsy and slowing down. They respond by becoming hyperactive and dysregulated. The mechanism is that chronic sleep fragmentation and nocturnal hypoxia impair prefrontal cortex function — the brain region that provides the cognitive brakes on impulsive behaviour — and this manifests as exactly the presentation that ADHD describes. The irony is that this presentation is arguably a physiologically appropriate response to an inadequately sleeping brain, not a pathological one, and it resolves when the underlying sleep problem is treated.
Studies estimate that 25 to 35 per cent of children diagnosed with ADHD may have an underlying sleep-disordered breathing problem. That means between 1 in 4 and 1 in 3 ADHD diagnoses in children may either be partially or entirely driven by an airway problem rather than primary ADHD. I want to be careful here: this does not mean that ADHD is misdiagnosed in all these children, nor that every child with ADHD should have their tonsils removed. It means that a sleep study should be part of the assessment pathway for children with attention and behavioural difficulties before an ADHD diagnosis is made permanent and a medication plan is initiated.
Between 1 in 4 and 1 in 3 children diagnosed with ADHD may have untreated sleep-disordered breathing as a contributor or primary driver. A sleep study costs less — and is less risky — than years of stimulant medication for a problem that might resolve with surgery.
A large randomised controlled trial, the Childhood Adenotonsillectomy Trial (CHAT trial), randomly assigned children with mild-to-moderate OSA to either early adenotonsillectomy or watchful waiting with supportive care. At seven months of follow-up, the surgery group showed significantly greater improvements in behaviour, quality of life, and on parent-rated symptom assessments compared with the watchful waiting group. The difference was not subtle.
Academic Performance: The Grade Level Gap
A 2015 meta-analysis — a study that pools results from many separate investigations — examined academic performance in children with sleep-disordered breathing versus healthy peers. The effect sizes found across three subjects were -0.31 in language arts, -0.33 in mathematics, and -0.29 in science. These are what statisticians call small-to-medium effect sizes.
To translate those numbers into practical terms: an effect size of 0.30 in educational research is roughly equivalent to one grade level of performance difference. A child with untreated sleep apnoea performs in language arts approximately as if they were a grade behind their peers — not because they are less capable, but because their capacity to learn, to consolidate information overnight, and to sustain attention during lessons is being systematically impaired by a breathing problem their teacher and parents may not know about.
After adenotonsillectomy, multiple studies show measurable improvements in academic performance, and follow-up assessments report significantly higher scores on cognitive and academic tests compared with pre-surgical baselines. These improvements are greatest in the first year after treatment — when the neurological recovery from chronic hypoxia and sleep fragmentation is most active — and continue over longer follow-up.
Sleep Architecture and Brain Development
The consequences of sleep apnoea during childhood are not simply about daytime performance. Sleep — and specifically slow-wave sleep and REM sleep — is the time when the brain does most of its developmental work during childhood and adolescence. Synaptic pruning (the process of refining neural connections), memory consolidation, emotional processing, and the integration of learning from the day all depend on intact sleep architecture. When sleep is fragmented by apnoea events night after night during the years when the brain is most actively developing, the consequences extend beyond current performance into the structural development of the brain itself.
Neuroimaging studies in children with OSA show changes in grey matter density in regions involved in attention, memory, and emotional regulation compared with healthy peers. Some of these changes normalise after treatment, but some studies suggest that prolonged untreated OSA during developmental years may leave lasting neurological traces. The implication is that the urgency of treatment in children is high — not just for their current quality of life, but for the developmental trajectory of their brains.
Growth and Hormonal Effects
Growth hormone in children, as in adults, is released predominantly during slow-wave (deep) sleep. In children with OSA, the repeated disruption of deep sleep impairs growth hormone secretion. The clinical consequence is growth retardation: children with significant untreated OSA grow more slowly than their peers, a finding that has been well documented in the paediatric sleep literature. After adenotonsillectomy, catch-up growth is commonly observed, with treated children showing accelerated height and weight gain in the months following surgery. This is sometimes referred to as "catch-up" or "rebound" growth and is one of the cleaner clinical demonstrations of the OSA-growth hormone link.
A 2022 meta-analysis found that enuresis — bedwetting — is significantly more common in children with sleep-disordered breathing than in healthy peers, with an odds ratio of 2.76. This means children with OSA are nearly three times as likely to wet the bed compared with children without the condition. To express that as a real-world comparison: bedwetting affects roughly 1 in 10 children aged 7. With OSA, that rises to closer to 1 in 4. The proposed mechanism involves elevated atrial natriuretic peptide production (a hormone released when the heart is under the repeated pressure of apnoea events), which suppresses the antidiuretic hormone response that should concentrate urine during sleep. Treatment with adenotonsillectomy substantially reduces enuresis in affected children, often resolving it entirely.
Treatment: Surgery and its Outcomes
Adenotonsillectomy — removal of the tonsils and adenoids — is the most effective and most commonly indicated treatment for paediatric OSA. The surgery is safe, well-established, and typically performed as a day procedure or with a single overnight stay. OSA-specific polysomnography outcomes following adenotonsillectomy show normalisation of apnoea-hypopnea index in the majority of children without obesity.
Post-surgical improvements are documented across multiple domains: behaviour improves significantly on standardised assessments within three to six months; quality of life scores improve substantially for both child and family; academic performance improves in the months and years following surgery; sleep architecture normalises; and growth velocity increases. In children whose ADHD-like symptoms were driven primarily by the sleep disorder, the behavioural changes after surgery can be dramatic enough that ADHD medication, if it has been started, is no longer required.
In children with residual OSA after adenotonsillectomy — particularly those with obesity or craniofacial differences — additional treatment with CPAP or other interventions may be needed. The threshold for treating paediatric OSA in the UK has historically been set relatively high, and I believe the evidence described on this page argues for lower thresholds and faster intervention, particularly in children showing behavioural or academic difficulties that are unexplained by other causes.
References
[1] Galland BC et al. Sleep disordered breathing and academic performance: a meta-analysis. Pediatrics. 2015. Effect sizes -0.31 (language arts), -0.33 (mathematics), -0.29 (science) for children with sleep-disordered breathing versus healthy controls; these are roughly equivalent to one grade level of academic underperformance.
[2] Chervin RD et al. Inattention, hyperactivity, and symptoms of sleep-disordered breathing. Pediatrics. 2002. Large cohort; ADHD-like symptoms 3-fold more prevalent in children with sleep-disordered breathing versus controls.
[3] Marcus CL et al. A randomized trial of adenotonsillectomy for childhood sleep apnea. New England Journal of Medicine. 2013. CHAT trial; RCT comparing early adenotonsillectomy vs watchful waiting; surgery group showed significant improvements in behaviour, quality of life, and symptom scores at 7 months.
[4] Bonuck K et al. Sleep-disordered breathing in a population-based cohort: behavioral outcomes at 4 and 7 years. Pediatrics. 2012. Large longitudinal cohort; estimated 25-35% of children with ADHD diagnoses have underlying sleep-disordered breathing.
[5] Zhang Y et al. Association between adenotonsillectomy and academic performance in children: a systematic review. JAMA Otolaryngology. 2019. Systematic review; significant post-surgical improvements in cognitive and academic performance compared with pre-surgical baselines.
[6] Chen X et al. Nocturnal enuresis and sleep-disordered breathing in children: a meta-analysis. European Journal of Pediatrics. 2022. Meta-analysis; OR 2.76 for bedwetting in children with sleep-disordered breathing; significant improvement in enuresis rates after adenotonsillectomy.
[7] Rosen G et al. Growth and sleep in children: an update. Sleep Medicine. 2023. Review of growth hormone secretion and growth retardation in paediatric OSA; catch-up growth documented post-adenotonsillectomy in multiple cohort studies.
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