Baby Snoring and Sleeping With Their Mouth Open

Why a blocked nose turns into an open mouth

Basis, the Durham University-linked Baby Sleep Information Source, gives the anatomy in one line: babies "are predominantly nose-breathers so they can suck and breathe at the same time". That is why a small amount of nasal congestion has an outsized effect. An adult with a stuffy nose breathes through their mouth without noticing. A baby has to work at it, and the result is snuffling, snorting, an open mouth, and a feed that keeps stopping.

Basis also notes that babies can make loud breathing sounds for this reason, and that swallowing and gurgling noises are usually down to an immature swallow reflex and a tendency to bring up a little milk. Noise on its own is not a diagnosis.

Occasional versus most nights

This is the distinction that decides everything. A baby who snores when they have a cold, and stops when the cold clears, is congested. A baby who snores most nights, cold or no cold, is worth raising with a doctor.

The American Academy of Pediatrics lists the signs of sleep apnoea in children as frequent snoring, problems breathing during the night, sleepiness during the day, difficulty paying attention and behaviour problems, and says that if you notice any of them you should let your doctor know right away. In young children the usual cause is enlarged tonsils and adenoids blocking the airway during sleep, which is why the most common treatment is removing them. Untreated, the AAP says sleep apnoea in children can lead to heart, behaviour, learning and growth problems.

The NHS pages are written for adults

Worth saying plainly, because it catches people out. The NHS pages on snoring and on sleep apnoea are general pages aimed mainly at adults. The snoring page suggests losing weight, sleeping on your side and avoiding alcohol, none of which applies to a baby, and its side-sleeping suggestion is the opposite of infant safer sleep advice. Use them for the symptom list — breathing that stops and starts, gasping, snorting or choking noises, loud snoring — and take the age-specific guidance from the AAP or from your own GP.

Who is more likely to have it

The AAP lists the children at higher risk of obstructive sleep apnoea, and the list explains why some babies are referred quickly. Children with larger-than-normal tonsils and adenoids are the biggest group, though it notes that not every child with large tonsils and adenoids has sleep apnoea. Babies with low muscle tone, with conditions affecting the shape of the face or jaw, and those born prematurely are also assessed more readily. If your baby is in one of those groups and snores most nights, say so when you book, because it changes the urgency.

The 999 threshold

Snoring and pauses are not the same thing, and the AAP gives a hard line for the pauses. Call 999 — 911 in the United States — immediately if your baby's breathing stops for more than 20 seconds, if their skin turns pale, bluish or greyish, if there is a change in muscle tone, or if the episode comes with fever or other signs of illness. Shorter pauses that come and go in an otherwise well baby have a separate explanation of their own, and are not what this page is about.

What to do about the congestion, and what not to do

For an ordinary cold, the NHS advice is unglamorous: most coughs and colds in babies clear on their own, and a baby who is feeding, alert and comfortable does not need treatment. Saline drops before feeds are commonly suggested by health visitors. Keeping the room at 16 to 20C helps.

What must not happen is any change to the sleep surface. Do not raise the head of the cot, put a pillow or a folded towel under the mattress, or use a wedge, a positioner or an inclined seat. The Lullaby Trust's guidance on a baby's airway is that anything holding a baby in a seated or inclined position can restrict their breathing, and it advises against soft-sided pods, nests, positioners, bouncy chairs and swings for sleep. A congested baby still sleeps on their back, on a firm flat mattress, in a clear cot.

Signs the cold is becoming something else

Get urgent help if your baby is taking less than half their usual feeds, has had no wet nappy for 12 hours or more, is breathing fast or noisily, is drawing their ribs in with each breath, has a temperature of 38C or above under three months, or seems very tired, floppy or irritable. Blue, grey or very pale skin, long pauses in breathing or grunting with every breath are 999 calls.

Positions, and what they can tell you

Parents often report that their baby only breathes quietly in a particular position, which is worth mentioning to a doctor and is not a reason to change where your baby sleeps. Sleeping with the neck extended, or consistently seeking an unusual posture to breathe comfortably, is one of the things clinicians ask about when assessing obstructed breathing in children, and it belongs in the consultation rather than in a cot modification at home.

What to bring to the appointment

Three things make a GP appointment about night breathing far more productive. A short phone video of your baby asleep during a typical noisy stretch, taken with the room quiet enough to hear. A rough sense of how many nights a week it happens, and whether it is present when your baby is completely well. And your baby's weight trend from the red book, since the AAP lists growth problems among the consequences of untreated obstructive sleep apnoea in children. If your baby has been snoring since birth rather than since a cold, say so, because congenital causes of a narrow airway are assessed differently.

When to ask

Speak to your GP if your baby snores most nights, sleeps with their mouth open when they are not congested, sweats heavily during sleep, sleeps in unusual positions with their neck extended, has pauses in breathing you can see, or is not gaining weight as expected. A phone video of a typical night is genuinely helpful evidence to bring.