Mouth Breathing: Why the Mouth Stays Open
Written by the Inclusive Developmental and Therapy Center therapy team — our Speech & Language Therapist, psychology and ABA staff. Clinical reviewer for this site: Dr Muhammad Suffyan, MB BS (GMC 8023727) · Updated August 2026; this page has changed since our last clinical review.
A child whose mouth sits open at rest is usually trying to breathe. Relatives say close your mouth, stand up straight, stop looking lazy. The mouth is open because the nose is not doing the job — a cold that never quite ends, adenoids, allergy, or a night of snoring that leaves them dry-lipped by breakfast.
That open posture changes the tongue, the saliva, the face of the sounds, and the quality of sleep. It is why this page sits next to glue ear, drooling and teeth grinding. Speech work on a blocked airway is a wasted term.
Mouth breathing, snoring, or sleep apnoea?
They overlap. They are not the same sentence.
- Mouth breathing by day. Lips apart at rest, dry lips, a dull look, a voice that sounds stuffed. Often a blocked nose. The tongue sits low and forward because it has nowhere else to go.
- Simple snoring. Sheffield Children’s NHS notes that just over 1 in 10 children in the UK snore regularly, and most of that is “simple snoring” — noise without serious blockage. Cornwall NHS guidance puts snoring at about 4–5% of five-year-olds, usually from large adenoids and tonsils, and often worse with a cold.
- Obstructive sleep apnoea (OSA). The same Sheffield leaflet: just under 2 in 100 children. Great Ormond Street puts it at 1–3%. The throat relaxes in sleep, air is blocked for a few seconds, the brain briefly wakes the child so they can breathe, and nobody in the house calls it a wake. You hear pauses, gasps, or a silence then a snort. Daytime: inattention, irritability, poor school, sometimes faltering growth.
In otherwise healthy children, enlarged adenoids and tonsils are the usual cause. Down syndrome, cerebral palsy, obesity, and a cleft or a small jaw raise the risk sharply. That is an ENT and paediatric picture, not a “close your mouth” chart.
How it shows up as a speech or school problem
A low, forward tongue is a poor starting place for t, d, n, l, s. You may hear a lisp, a wet chin, or speech that sounds as if the nose is full — or oddly as if too much air is coming through the nose. See nasal speech if the sound is the worry, and lisps if it is S.
Sleep that is chopped into fragments looks like ADHD by 8am: fidgety, short-fused, “not listening.” Before anyone starts a behaviour plan, ask whether they snore, sleep with the mouth open, or wake dry-mouthed. Glue ear likes the same children — blocked nose, adenoids, winter colds.
What to do this week
- Watch one night, honestly. Mouth open? Snoring every night, or only with a cold? Pauses, gasps, sitting up to breathe, sweating, odd sleep positions? Morning headache or a voice that is still blocked?
- See a doctor if there are pauses, poor growth, or snoring every night with daytime problems. That is ENT, not speech homework. Adenoids and tonsils are a surgical conversation we will not have for you.
- Treat the nose if it is the obvious door. A cold, allergy, or a child who never breathes through the nose. Follow the paediatrician. Oil in the nose from a neighbour is not a plan.
- Do not run “lip taping” or mouth-closing gadgets on a sleeping child. If they cannot breathe through the nose, you have blocked the only airway they have.
- Speech and drooling work after the air is moving. Closed-lip play, a swallow cue, sounds that need the tongue tip up — those belong once they can breathe with the mouth shut for more than a few seconds. Until then, we will say so.
What we do in Multan
Inclusive Developmental and Therapy Center does not diagnose sleep apnoea, does not look at adenoids, and does not operate. We notice the open mouth, the lisp, the wet collar, the child who cannot sit because they slept in fragments, and we send you to ENT when that is the next adult.
If hearing is muffled as well, start with a hearing test — hearing and speech. If the mouth is open and saliva spills, read drooling. If grinding and snoring travel together, read bruxism and still go to the doctor about the night breathing.
A consultation is Rs 1,500 and lasts up to 50 minutes. A phone video of sleep (if you already have one) is more useful than a description. We will not watch it as a diagnosis. We will use it to decide whether the next message is to us or to ENT.
Frequently asked questions
Is mouth breathing just a bad habit?
Usually not. The mouth stays open because the nose is blocked, the adenoids are large, or sleep breathing is hard. Telling a child to close their lips does not open the nose. See a doctor if they snore most nights, pause in their sleep, or cannot keep the mouth shut even when you ask.
Does mouth breathing delay speech?
It can get in the way of sounds that need the tongue tip up — t, d, n, l, s — because the tongue sits low and forward. It is not a full speech delay on its own. Fix the airway, check hearing, then look at sounds. Drilling S while they can only breathe through the mouth is a poor plan.
When is snoring a problem?
Snoring only with a cold is common. Snoring most nights, pauses or gasps, restless sleep, daytime inattention, or poor growth needs a doctor. Sheffield Children’s NHS: just over 1 in 10 children snore regularly; just under 2 in 100 have obstructive sleep apnoea. We do not diagnose that here.
Will taking out the adenoids fix the speech?
Sometimes the mouth closes and the sounds get a better chance. Sometimes glue ear and a lisp remain. Adenoid or tonsil surgery is an ENT decision. We will not recommend an operation, and we will not pretend speech therapy replaces one.
Can you teach my child to breathe through their nose?
We can practise closed lips in play once the nose actually works. We cannot breathe for a blocked airway. If they cannot get air through the nose, the next appointment is medical.