Teething and Sleep – what does the science have to say?


Many of you will know about my science background… When things are in doubt I dive into the research, so let’s take a look at what the science says about teething.

My first finding was that none of the symptoms of teething are scientifically proven.

Most studies found a flat-out “no” to the question of a significantly raised temperature, although one reported a rise in body temperature only on the day the tooth actually erupts and cuts through. Even then, temperature variations topped out at a barely perceptible 0.39°C.

But what about the rest?

The diarrhoea and nappy rash that seems to occur when a tooth is on its way?

Popular opinion here is that an increase in saliva leads to more acidic stools, but the science for this just doesn’t stack up. For starters, the pH level of our stomachs is already 1.5-3.5, which is incredibly acidic.

Our saliva, on the other hand, has a pH of 6.2-7.6, which means it’s basically neutral or slightly on the alkaline side. If we could consume enough saliva to influence our stools, it would make it more alkaline.

Even if it did become acidic, something that could burn the bottom would also be burning the skin off their mouths. Diarrhoea is more likely the result of a virus (rotovirus or ecoli) or – less commonly – lactose intolerance. The saliva-acid idea we must chalk up to a physiologically impossible myth.

Some of the other symptoms may have a bit more of a basis; the redness in the cheeks, increased irritability, increased salivation (drooling), and gingival irritation (a sore mouth) have been found in the minority of cases.

However, what came across constantly was that teething is a natural physiological process that usually occurs without problems. Another study I came across found that of 50 babies that were hospitalised for “teething symptoms”, 48 were found to have another organic cause for their illness.

This is not to say that our babies don’t experience discomfort when they are cutting a new tooth. However, the symptoms are usually very mild and therefore any disturbance to their sleep is also very mild. If your child is experiencing major sleep issues, it’s likely to be something else.

The other way that it’s easy to tell is looking to their temperament during the day. I maintain that teeth growing is not a strictly nocturnal activity, so if they are distressed in the evening due to a tooth, they will be during the day too.


The appearance of teeth tends to follow a fairly normal pattern: incisors, canines, then molars. Studies that did cite any symptoms found these to be worse for the first teeth our babies get.

The period of teething also coincides with a reduction in immune function and a switch for our babies from passive to active immunity. Basically, this means that they’re losing the antibodies they’ve had from their mum (through pregnancy and potentially breastfeeding) and are now having to make antibodies themselves.

This lowered immune function comes at a time when they’re starting to put their hands in their mouths much more, and while their gums are erupting and raw. It follows then that this is a time of increased infections, from upper respiratory to middle ear and urinary tract.


…increased saliva could correlate to our little one’s salivary glands kicking in, as happens when they need amylase and further enzymes for the introduction of solids.

So, not only are your baby’s first teeth the most likely to cause a problem, they are also the ones that grow when our children are younger, with less of their immune system developed and while their bodies are undergoing a huge number of other changes.


Teeth generally start to emerge between 6-8 months, which we know is a time of huge changes not only for our babies’ bodies, but also for their brains and development. I’ve looked at the causes of sleep issues at this age before – including learning to roll, learning to resettle, transitioning down to two naps from three, and being ready to be un-swaddled.

All these things are likely to spark sleep issues; however, they are all things that are completely resolvable.

Perhaps there is a night that your little love is cutting a tooth and needs an extra cuddle; these small blips are natural. However, to avoid the slippery (and all too easy) slope of habitual wake-ups, we need to be confident the next day to stick to good sleep habits.

Sleep disturbances (from teething or otherwise) can quickly lead to overtiredness, which can really keep you stuck.


The results here say that numbing creams, like bonjela and the like, don’t work as our babies produce too much saliva for them to be effective. Similarly, Pamol is not usually recommended. In fact, any pharmacological treatment should be monitored carefully.

So, what can you do? The only two treatments found to be effective in easing symptoms were an ice-cold flannel or toy to chew on, or the simply-can’t-beat-it comfort of ‘cuddle therapy’.

Anecdotally I believe that the way that some other treatments appear to work is because they are often administered with a cuddle too; it is likely the latter that made the difference.


As well as setting the record straight more generally about what can, and can’t, be attributed to teething, there’s another important reason for writing this post.

As one article I came across attested “the suboptimal management of the common patterns [that we attribute to teething] are causing us to miss serious illnesses.”

The science states that any teething symptoms are minor and relate to discomfort rather than physical illness, so if your baby is unwell, it’s likely that they’re actually unwell. That may well require an altogether different treatment.

If your baby has a fever or diarrhoea (which can be particularly dangerous in infants and lead to dehydration), seek medical advice.

Similarly, if they have little or no appetite for days, or become really irritable day after day, see your doctor – there could be something else going on that they are unable to communicate. And, if it is a sleep issue in and of itself, reach out and we’d be happy to help.

Emma Purdue

Emma is the owner and founder of Baby Sleep Consultant, she is a certified infant and child sleep consultant, Happiest Baby on the block educator, has a Bachelor of Science, and Diploma in Education. Emma is a mother to 3 children, and loves writing when she isn’t working with tired clients and cheering on her team helping thousands of mums just like you.

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