What Causes Bad Breath? Understanding Halitosis in Childhood
Posted on April 11th, 2025 | GEkidds
As parents, we’ve all experienced it— leaning in for a kiss only to be met with not-so-fresh breath from our little one. If you’ve noticed your toddler’s breath often smells unpleasant or your child has bad breath even after brushing, you’re not alone. Bad breath in kids is actually quite common, but it can leave parents wondering about the cause and how to fix it.
If you’re concerned about childhood bad breath, continue reading. In this blog, we’ll explore why kids get bad breath and what you can do to help your child avoid it.
Common Causes of Bad Breath in Kids
Poor Oral Hygiene
The most common reason for bad breath in children is simple: Not brushing or flossing well enough. Food particles left in the mouth feed bacteria, and these bacteria create smelly gases. When your child has bad breath even after brushing, they might be:
- Missing certain areas in their mouth when brushing
- Brushing too quickly (less than two minutes)
- Not cleaning their tongue, where many bacteria live
- Skipping flossing, which cleans between teeth where brushes can’t reach
Even infants can have bad breath due to milk residue on the tongue or around the gums. Halitosis in infants often improves with gentle cleaning using a damp cloth or gauze.
Dry Mouth
Our mouths need saliva to wash away food and bacteria naturally. When your child’s mouth gets dry (especially if they breathe through their mouth at night), bad breath can develop. This is why many kids may have “morning breath.” Mouth breathing due to seasonal allergies, enlarged tonsils, or a stuffy nose can lead to dry mouth and bad breath, too.
Certain Foods
The foods your child eats affect how their breath smells. Strong-smelling foods like onions, garlic, and some spices can cause temporary bad breath. When these foods are digested, their smelly compounds enter the bloodstream and travel to the lungs, where they can be breathed out.
This is why your child may have bad breath even after brushing— the smell isn’t just in their mouth but is coming from their lungs as they breathe.
Infections and Illness
Sudden bad breath in toddlers or older children can signal an infection. Conditions that can cause halitosis include:
- Sinus infections
- Strep throat
- Tonsillitis (when the tonsils become infected)
- Dental infections or abscesses
If your child or toddler has bad breath along with a sore throat, fever, or mouth pain, it’s time to call the doctor or dentist.
Gum Disease and Tooth Decay
Even children can develop early forms of gum disease, which often causes bad breath. If you notice your child’s gums look red, puffy, or bleed easily when they brush, gum problems might be causing their smelly breath. Cavities can also be linked to foul-smelling breath due to bacterial activity and food that gets trapped in crevices and breaks down.
Foreign Objects
Young children sometimes put small objects in their nose, which can get stuck and cause bad breath. If your toddler’s breath smells particularly foul and has changed suddenly, check their nose for any foreign objects.
This is more common than you might think! Small items like beads, toy parts, clay, or even food can get lodged in a child’s nose and cause a very distinct smell.
Improper Cleaning of Oral Appliances
All appliances that go in your child’s mouth need regular cleaning. This includes athletic mouthguards, night guards, orthodontic retainers, and dental space maintainers. If these appliances are not cleaned well, bacteria can build up, which can cause bad odors in your child’s mouth.
Digestive Issues
Sometimes, infant bad breath can be linked to digestive problems like acid reflux. When stomach acid backs up into the throat or mouth, it can cause a sour smell.
If your baby has bad breath along with frequent spitting up, fussiness after eating, or poor weight gain, talk to your pediatrician about the possibility of stomach issues. Acid reflux and other conditions that affect the digestive system can lead to bad breath in school-aged children and teens, too.
How To Treat and Prevent Bad Breath
Improve Oral Hygiene
Make sure your child brushes their teeth twice a day for two minutes each time. Supervise young children’s brushing and flossing to make sure they’re doing a thorough job.
Don’t forget to help your child clean their tongue gently with their toothbrush or a tongue scraper. The tongue can harbor lots of bacteria that cause bad breath. For infants, gently clean their tongue and gums with a soft, damp cloth after mealtimes.
Stay Hydrated
Encourage your child to drink plenty of water throughout the day to wash away food particles and bacteria. Drinking water is especially important after eating sugary, sticky, or acidic foods.
Regular Dental Check-Ups
Bring your child to the dentist for regular check-ups and teeth cleanings. At Glen Ellyn kiDDS Pediatric Dentistry and Orthodontics, we can spot and treat problems like cavities or plaque buildup that might be causing bad breath.
Check for Illness
If your child has sudden bad breath along with other symptoms like fever, sore throat, or congestion, consult with their pediatrician. Treating the underlying illness often resolves the breath issue.
Healthy Diet
Limit sugary and processed foods, which feed the bacteria that cause bad breath. Encourage crunchy fruits and vegetables like apples, carrots, and celery, which help clean teeth naturally as your child chews.
When To See a Dentist About Your Child’s Bad Breath
While occasional bad breath is normal, you should contact a children’s dentist if:
- Your child’s bad breath persists despite good oral hygiene
- Bad breath is accompanied by other symptoms like bleeding gums or mouth pain
- Your child has white or red patches in their mouth
- Your child has a bump on their gum tissue
- Infant bad breath doesn’t improve with regular gum cleaning
Our team at Glen Ellyn kiDDS understands the most common causes of halitosis in young patients. If your child has chronic bad breath, give us a call now. We can help determine if your child’s bad breath stems from a dental issue and recommend appropriate treatment.
Schedule Your Child’s Visit
If you’re concerned about your child’s bad breath or it’s time for their regular check-up, contact Glen Ellyn kiDDS Pediatric Dentistry and Orthodontics to schedule an appointment. Our friendly team provides gentle, compassionate care that helps kids feel comfortable at the dentist.
Remember, most causes of bad breath are easily treatable. Addressing them early helps establish good oral health habits that last a lifetime. We’re here to partner with you in keeping your child’s smile healthy and fresh!
