Reasons for Bad Breath in Kids

We think of children as having sweet smelling breath, but sometimes even an adorable little toddler can have stinky breath. Most cases of bad breath in children result from simple-to-resolve issues, such as poor dental hygiene, but sometimes bad breath can indicate a more serious problem 12. If bad breath does not seem to have a straightforward cause, talk with your child's pediatrician or dentist 2.

Poor Dental Hygiene

One of the most common causes of bad breath in kids is poor dental hygiene 2. The Centers for Disease Control and Prevention recommends that kids brush their teeth at least 2 times per day, using a fluoride toothpaste if they're over the age of 2, to reduce tooth decay. Teach your child to brush her tongue as well as her teeth. Flavored floss and a rotary tooth brush can make brushing more enjoyable and effective. Never give children younger than 2 mouthwash or fluoride toothpastes, which can be harmful when swallowed. Kids should also avoid breath mints which usually contain sugar and encourage bacterial growth.

Dry Mouth

During the day, our saliva washes away most debris and bacteria in the mouth that can cause bad breath 12. At night, we produce less saliva and swallow less frequently. Consequently, odor-causing bacteria builds up, leading to morning breath 3. Any time your child breathes through her mouth, such as when her nose is congested, it can lead to a dry mouth and bad breath 2. Dry mouth can also be caused by thumb sucking, chewing or sucking on a blanket or by certain medications. Sugar-free gum or sour candies encourage saliva production.

Nasal Issues

If your child has an infection or congestion in the sinuses or nasal cavities, the post nasal drip can lead to bad breath 2. If your child has stuck something up his nose, that can lead to an infection which causes bad breath as well as a smelly discharge and odor emanating from the nose 23.


Tonsillitis can cause bad breath in children, especially if food gets caught in the crevices of the tonsils 12. If the tonsils have pockets of infection which open and begin to drain, the resulting products of infection can lead to bad breath 2. If your child has bad breath along with other symptoms of an illness, a visit to the pediatrician is in order 2.


Breath that smells like acetone, which has a fruity odor, is a symptom of diabetes 3. Breath that smells like acetone can also occur if your child has ingested alcohol, salicylates, acetone or phenol. If your child has breath that smells like acetone, contact your pediatrician or poison control center immediately.

Unusual Odors

Bad breath can often have an unpleasant or offensive smell but normally goes away with time 2. If your child's foul-smelling breath persists or has an unusual odor, such as the smell of violets, ammonia, celery, bitter almonds or dead fish, for example, it can indicate a serious medical condition 3. If you have questions about bad breath in your child, contact your child's pediatrician or dentist, immediately if the breath has an unusual odor 23.