Causes of Infant Bad Breath and When to Worry

woman wiping baby’s mouth

When you think of bad breath, you generally don't think of a baby. After all, babies smell sweet unless they need their diaper changed, right? The fact is that while it is not all that common, infant bad breath may indicate that something is wrong.

Medical Causes of Infant Bad Breath

If your baby has bad breath, you'll need to search for the cause. Most of the time, bad breath in young children may be a sign of infection. But the causes of a baby with bad breath are varied. Bad breath in infants and newborns should not be dismissed because it may signal an infection in the mouth or throat. In rare instances, bad breath can be a sign of a more serious condition.

Pediatric Sinusitis

One possible reason for foul breath could be sinusitis. According to the American Academy of Otolaryngology-Head and Neck Surgery, symptoms of pediatric sinusitis include bad breath, nasal discharge, fever, irritability, and a nasal drip. While sinusitis symptoms mirror cold symptoms, sinusitis lasts longer than a cold, usually more than 10-14 days. The condition can be the result of allergies or a viral illness.

Pediatric sinusitis causes stuffy sinus passages. As a result, the baby breathes solely through her mouth which dries saliva. Less saliva than normal leads to a dry mouth, which may create bad breath. If you suspect a sinus infection or other illness, schedule an appointment with your health care provider to determine if your baby needs medication.

Enlarged Tonsils

Another condition that can lead to stinky breath is enlarged tonsils or adenoids. Healthy tonsils are generally pink and spot-free, but infected ones are red, swollen, and can have noticeable white spots. Medical experts note that the condition can lead to nosebleeds or cough, in addition to bad breath.

Enlarged tonsils and adenoids can result from an infection but may also be normal. If an infection is the cause, bacteria collects in the back of the throat and, paired with the sour smell of infection, can cause stinky breath. If your child's tonsils look swollen or red, seek the care of your healthcare provider. Your pediatrician may prescribe an antibiotic to help take care of the infection.

Acid Reflux

Acid reflux can cause bad breath in infants. According to the National Institutes of Health (NIH), the condition is generally accompanied by the regurgitation of food. Acid reflux happens because the ring of muscle between the esophagus and the stomach is not yet fully mature and as a result, stomach contents flow backward resulting in your baby spitting up. This condition is rarely serious and should decrease as your baby gets older, according to the NIH. Acid reflux usually does not continue after the age of age 18 months.

Reflux in babies usually clears up by itself but there are a number of things you can do to help alleviate symptoms:

  • Give your baby smaller, more frequent, feedings.
  • Burp your baby partway through her feeding.
  • Hold your baby upright for 20 to 30 minutes after feeding.
  • Try switching the type of formula you feed your baby.
  • Try using a different size nipple on your baby bottle. Nipples that are too large or small can cause your baby to swallow air.
  • If you're breastfeeding, try eliminating dairy products, beef, or eggs from your diet, to test your baby for allergies.

Medications aren't normally recommended for infants with uncomplicated reflux. Your pediatrician may suggest trying an acid-blocking medication such as Zantac for babies 12 months or younger or Prilosec for toddlers age 1 year or older. Controlling your baby's acid reflux may eliminate her foul breath.


Type one diabetes occurs when your child's pancreas stops producing insulin, a hormone that helps your body get energy from food. When this happens, the body's immune system attacks and destroys the cells that produce insulin in the pancreas (beta cells).

There are a number of symptoms that may be related to this condition. Studies suggest that foul breath and poor oral health can occur. Medical experts advise that children with diabetes practice good oral care and have regular dental visits.

Chronic Kidney Disease

Chronic kidney disease (CKD) can occur when there is irreversible kidney damage or a reduction in kidney function. Medical sources report that children under the age of 2 account for about 15% of the total reported cases of CKD. Symptoms of chronic kidney disease can include:

  • Poor appetite
  • Vomiting
  • Headache
  • Stunted growth
  • General feeling of sickness
  • Chronic urinary tract infections
  • Urinary incontinence
  • Bad breath
  • Stomach mass

Other Causes of Baby Bad Breath

Bad breath in babies is not always the result of a health condition. The food or drinks you provide to your baby may stick to the tongue or around the gums and cause bacteria to grow, which in turn, causes the rotten smell. The growth of most odor-causing bacteria can be accelerated by less serious triggers like thumb sucking and using a pacifier, for example.

Thumb Sucking

Baby Girl

The University of Chicago reports that about 80% of infants and children suck their thumbs. Thumb sucking can lead to a dry mouth, increased bacteria, and ultimately, bad breath.

Most children give up the habit between the ages of 2 and 4. Approximately 12% of children still suck their thumbs at age 4.

Young children under the age of 4 don't require any treatment to stop the habit. So parents should wait to see if their child stops the behavior without intervention. To help alleviate infant bad breath that's caused by thumb sucking, use a warm, soft washcloth to clean your baby's mouth, gums and tongue regularly.

Pacifier Use

When your baby sucks on a pacifier, saliva and oral bacteria are transferred onto the pacifier. This may result in an unpleasant-smelling pacifier which can then be transferred to your baby's mouth the next time she sucks on the pacifier.

Also, if a pacifier is used multiple times without cleaning, this allows bacteria to multiply more quickly. To eliminate the stench of bad breath, you can stop using a pacifier altogether. If your baby isn't ready to give it up, take time to sterilize it often to kill the bacteria and germs present.

Most children will stop using pacifiers between the ages of 2 and 4 years old. If your child is reluctant to give up the pacifier consider talking to your pediatrician or dentist for tips.

Dietary Sugar

When bottle-fed babies are put to bed with milk or formula, this can lead to bacterial growth in the mouth and ultimately bad breath, according to the American Dental Association. To minimize bad breath and oral bacteria, practice good oral care with your baby.

  • Wipe down your baby's gums at least twice a day especially after feedings or before bed. Wiping her gums will wash off bacteria and prevent it from clinging to gums.
  • If your baby depends on a bottle to help him fall asleep, switch it out for a bottle of water which will not encourage the growth of bacteria that leads to bad breath.
  • If your baby is a little older, a diet that includes sugary drinks and other treats like pudding can help bacteria grow and cause bad breath.

Foreign Object

Occasionally babies lodge small foreign objects such as a pea or a piece of a toy in their nose without your knowledge. Not only does this cause poor breathing but it can also cause bad breath.

If you believe that this is the reason for your child's bad breath, see your health care provider as soon as possible so she can check your child's nasal passages and remove the object.

Infant Bad Breath: Treatment and Prevention

If your baby suffers from bad breath, it is best to bring the problem to your pediatrician's attention. The doctor will be able to diagnose sinusitis, infections, or other health conditions that may be the culprit behind your baby's bad breath. Also, keep your baby's mouth clean and reduce the use of items that increase bacteria and cause bad breath. Providing your loved ones with good oral care will help them maintain fresh breath.

Trending on LoveToKnow
Causes of Infant Bad Breath and When to Worry