What Causes My Child to Have Bad Breath?

Being a parent and bringing up kids is tough and is a full-time job in itself. Bringing up kids requires you to have eyes in the back of your head 24/7, and to have at least six pairs of hands. 

Children can be accident prone, they need feeding, they need bathing, they need clothing, and of course they require attention. Of the many issues and questions about raising kids that you may have, you could very well find yourself asking what causes my child to have bad breath? 

Getting a young child to practise good oral hygiene is like trying to plait fog. Okay, that’s perhaps a bit of an over exaggeration, but it is tough. If your child isn’t practising good oral hygiene, or if they have bad breath for no obvious reasons, it could be time to visit a specialist and get to the bottom of what may be the culprit. 

You may wonder why my child has bad breath all of the time, but worry not, because we’ll be getting to the bottom of what’s wrong in today’s article. 

Causes of bad breath in children and teenagers

Bad breath in kids (even after they brushed their teeth) could be due to a number of reasons. Let's explore some of these below:

Poor oral hygiene 

One of the most common causes of halitosis (bad breath) in children and teenagers is one which can thankfully be avoided, and that is poor oral hygiene. 

Children are generally not fans of brushing their teeth, and they’re highly unlikely to floss voluntarily, and this can lead to bad breath. Not brushing the teeth or flossing can allow small remnants of food to become stuck between the teeth, which can then breed bacteria and begin to rot and degrade in the mouth. 

Needless to say, rotten food swarming in bacteria won’t smell nice, and this can therefore result in bad breath. So, if you’re wondering what causes my child to have bad breath? It could be their oral hygiene, or lack thereof. 


Another common cause of bad breath in toddlers and teens is an infection. 

If you’re asking why does my child’s breath smell even after brushing their teeth? It could be down to an infection. 

Sinus infections or tonsil infections can cause bad breath due to bacteria. In the tonsils for example, swollen tonsils may result in bacteria collecting in the pit of the tonsils, which along with the smell of the infection in general, can result in some pretty toxic smelling breath. 

In the sinuses, if your child has a sinus infection, fluids can collect in the throat and nasal passages, which is swarming with bacteria, and again, you can guess what the end result will be. 


As well as infection, you may also find that a disease could be the culprit responsible for your child’s bad breath. 

Diabetes, liver issues, stomach issues, kidney failure, and certain strains of cancer such as mouth cancer could also be responsible. Now, we don’t want to alarm you, and it is highly unlikely that these are in fact responsible for your child’s bad breath, but as the saying goes ‘it’s better to be safe than sorry’. 

If your child does suffer with halitosis and there is no obvious reason for why that could be, it’s always best to seek professional medical advice, just to be sure. 

Tonsil stones 

Another reason for bad breath in kids is tonsil stones. 

Tonsil stones are small light-coloured lumps of matter that form in the tonsils. They’re typically made of minerals, especially calcium salts, that again breed odor causing bacteria. 

Tonsil stones are formed when debris from food, cells, tissues, and bacteria become wedged in crevices between the tonsils, before hardening through calcification. Until the stones are dislodged, they can harbour foul-smelling bacteria and can make the breath smell pretty noxious. 

Regular brushing and flossing can help to prevent tonsil stones, as can gargling with an anti-bacterial mouthwash, or a simple warm saltwater solution. 

Foreign objects 

Still wondering what causes my child to have bad breath? If so, a foreign object could be to blame. 

As mentioned, when looking after children, you need to watch them 24/7. Kids have been known to insert things in their nasal passages, including small items of food such as a baked bean or a piece of sweetcorn perhaps? 

If your child constantly has bad breath, a piece of food could be lodged in the nasal passage which has resulted in infection and an accumulation of bacteria as it rots and breaks down. Needless to say, this would cause bad breath and it would need removing professionally. 

Dry mouth 

If your child uses a pacifier, sucks their thumb a lot, or does a lot of mouth breathing, this could result in dry mouth. 

Dry mouth is basically a lack of saliva in the mouth, meaning bacteria isn’t washed away as much, and meaning that the teeth are more susceptible to rotting, cavities, and decay in general. 

One of the easiest ways to prevent dry mouth is to simply ensure your child is hydrated enough so as to produce plenty of saliva. 

Their dietary choices

And last, but by no means least, we have poor nutrition. 

Asking why does my child’s breath smell bad even after brushing their teeth? If so, their diet may be to blame. 

If your child eats a lot of strong-smelling foods such as onion, garlic, fish, and fermented food etc, the smell may linger after eating, resulting in bad breath. 

After being consumed, molecules from the food may find their way into the bloodstream, before passing through the lungs and being exhaled when they breathe. 

Low carb diets can also cause bad breath when the body enters a state of ketosis. Here, ketone enzymes may be present in the breath, resulting in bad breath. Unless medically prescribed however, no child or teen should be following a low carb diet. 

How to treat bad breath in kids

Now that we know some of the major causes of bad breath in children and teens, we’ll now take a look at some of the most effective ways to treat bad breath. These include, but are not limited to: 

  • Brushing their teeth at least twice a day
  • Ensuring they brush thoroughly 
  • Brushing their tongue 
  • Using an anti-bacterial mouth wash 
  • Helping your child to floss their teeth, providing they’re adult teeth 
  • Invest in a good quality electric toothbrush 
  • Regularly take your child to visit the dentist 
  • Have your dentist perform routine cleaning on your child during each visit 
  • Ask your dentist for toothpaste and mouthwash recommendations

The importance of regular dental check-ups

If you’re still asking why my child had bad breath all of the time, it’s important to book an appointment with a pediatric dentist.

A dentist can examine your child and get to the bottom of what may be causing their chronic bad breath. 

They may also refer you to another medical expert if there are no obvious causes for your child’s bad breath, just to help rule out anything more serious, or to get to the bottom of what may be causing the halitosis. 

Not only can dentists help diagnose possible halitosis causes and make referrals, they can also perform various oral hygiene procedures, and help teach you and your child good oral hygiene habits that will stick with them for the rest of their lives

Cant find what you're looking for?

We would answer any dental queries you may have. Our friendly team of dentists are only a call away.

Get in touch
20210308 THD ND 183 Lr

We accept all Major Health Funds and Medicare dental schemes

Hicaps Funds Insurance Brands Orig