Unusual Breath Odors & What They Mean

Unusual breath odors are common in kids. Typically there isn't anything to worry about, but there are some breath odors that indicate an underlying problem.

In children with good oral hygiene, smelly breath that persists throughout the day is most often the result of mouth-breathing, which dries out the mouth and allows the bacteria to grow. Saliva cleanses and rids the mouth of bacteria, so anything that causes dry mouth may cause bad breath as well.

Children who consistently breathe through their mouths might have colds, sinus infections, allergies, or enlarged tonsils or adenoids blocking the nasal passages, so a visit to the pediatrician is in order.

Thumbsucking or sucking on a blanket can also dry out the mouth. Dry mouth can also be caused by certain medications, so be sure to mention any medications and/or supplements your child is taking when you visit the pediatrician. 

For most children, bad breath is not associated with any serious conditions. However, here is a list of some uncommon, but telltale, odors.

Unusual Breath Odors:

  • Acetone (fruity smell) – diabetes or acetone, alcohol, phenol, or salicylate ingestion
  • Ammonia – some types of urinary tract infections, or kidney failure
  • Asparagus – eating asparagus (very unusual in children;>))
  • Bitter almonds – cyanide poisoning
  • Cat’s urine – odor of cats syndrome (beta-methyl-crotonyl-CoA-carboxylase deficiency)
  • Celery – Oasthouse urine disease
  • Dead fish – stale fish syndrome (trimethylamine oxidase deficiency)
  • Fresh-baked bread – typhoid fever
  • Foul – tonsillitis, sinusitis, gingivitis, lung abscess, dental cavities, tonsil stones, or gastroesophageal reflux  (some of these are actually quite common)
  • Garlic – arsenic, phosphorus, organic phosphate insecticides, or thallium poisoning
  • Horse-like (also described as mouse-like or musty) – phenylketonuria
  • Rancid butter – odor of rancid butter syndrome (hypermethionemia and hypertyrosinemia)
  • Raw liver – liver failure
  • Sweaty socks – odor of sweaty feet syndrome (Isovalryl CoA dehydrogenase deficiency)
  • Sweaty socks – odor of sweaty feet syndrome II (Green acyldehydrogenase deficiency)
  • Violets – turpentine poisoning

Three-year-olds often stuff items in their noses, and then forget about them. When my son Kevin was three, he put five peas up his nose before anyone found out! Watch for the combination of smelly breath and a smelly, yellow nasal discharge — especially from one nostril. You and I might not think of stuffing peas up our noses, but three-year-olds think outside the box!

Finally, children sometimes stuff items in their noses, and then forget about them. When my son Kevin was three, he put five peas up his nose before anyone found out! Watch for the combination of smelly breath and a smelly, yellow nasal discharge — especially from one nostril. You and I might not think of stuffing peas up our noses, but three-year-olds think outside the box.

References and Resourses

Amir E, Erica et al. Halitosis in children  The Journal of Pediatrics. 1999;134(3):338-343.   

Mace JW et al: The child with an unusual odor: A clinical resume. Clinical Pediatrics. 1976;15(1):57-62.

Rosenberg M: Clinical assessment of bad breath: Current concepts. J Am Dent Assoc. 1996; 127:475.

Last medical review on: June 14, 2020
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Hi Jason,

Clever response. I’ll give you points for that one ;)

@MsGreene
Note: I am the co-founder of DrGreene.com, but I am not Dr. Greene and I am not a doctor. Please keep that in mind when reading my comments and replies.

Does Arizona Uranium ingestion cause ‘flint sausage breath pillows’? I have it, now.

Hi Jason,

Clever response. I’ll give you points for that one ;)

@MsGreene
Note: I am the co-founder of DrGreene.com, but I am not Dr. Greene and I am not a doctor. Please keep that in mind when reading my comments and replies.

Same here! Totally ruining my life! I have tried everything and Nothing helps.

My husband’s breath smells like antifreeze. He is an alcoholic

As someone else said probably tonsil stones. Try looking at your tonsils in the mirror with a flashlight. If you see white spots its likely stones. Get a waterpik so that you get flush out tonsil crypts. You would start on lowest level and maybe not go past 2. Some people use a finger to push their tonsils, also bobbie pins and q-tips. Water pik works the best I think. Besides that brush well, floss daily and get see your dentist 2x a year.

You probably need your large tonsils taken out. Bacteria could get stuck behind and rotten food. Have u gargled your throat?

Hi I don´t really know how to put this so i´m just going to say it…my Pastor breath smell very bitter all the time…i´m always wondering way?
And i know if I smell it everyone does.

Can somebody help me

you might have tonsil stones

Is your baby Italian?

I hope your child is ok, as I see your question was posted in 2018. When my breath smelled like Poo, it was because my intestines had a bowel blockage. I had to have emergency surgery.

Are you working around Nuclear Rocket Fuel? If so, thereyou go!

My wife has a breath that smells like marijuana or digested grass. any ideas what may cause that?

could need a brush and how sweet?my granddaughter is 9mo also x
patty lopez

he has to brush
patty lopez

craig and i smoked a jazz cigarette and now our breath smells like hot dogs, garlic on hot dogs. my teeth also patty lopez

What a bummer. Have you talked to your doctor about this? Maybe the issue isn’t your mouth, but your digestive system.

I have been experiencing bad breath since Elementary school. I am currently 24 years old and still experiencing bad breath. It was first brought to my attention by my mom when I was younger. She embarrassed me a few times instead of helping me find out whats wrong with me. I have used all kinds of tongue scrapers including a spoon. I brush and floss twice a day as well as scrape my tongue. However, my breath still stinks. I have dry mouth a lot as well which cause my breath to smell like “poo”. It is really embarrassing. My son is 5 years old and he has told me my breath stinks as well. I know I am a very pretty girl but it doesn’t matter if my breath stinks. I hate to talk because I don’t want to offend anyone. I have tried chewing gum, mints, drinking water, taking vitamins. Nothing seems to help.

Same here! Totally ruining my life! I have tried everything and Nothing helps.

As someone else said probably tonsil stones. Try looking at your tonsils in the mirror with a flashlight. If you see white spots its likely stones. Get a waterpik so that you get flush out tonsil crypts. You would start on lowest level and maybe not go past 2. Some people use a finger to push their tonsils, also bobbie pins and q-tips. Water pik works the best I think. Besides that brush well, floss daily and get see your dentist 2x a year.

You probably need your large tonsils taken out. Bacteria could get stuck behind and rotten food. Have u gargled your throat?

you might have tonsil stones

What a bummer. Have you talked to your doctor about this? Maybe the issue isn’t your mouth, but your digestive system.

uhh thats a sign of a stroke…

My wife and kids compliant that my breath sometimes smells like poop or sometimes like batteries, especially when I come back home after work. It is my mouth, sinuses or post nasal drip

Are you working around Nuclear Rocket Fuel? If so, thereyou go!

My mouth tastes like burnt popcorn or smoke. I don’t smoke and never around smoke. What could be causing this?

uhh thats a sign of a stroke…

Hi my breath smells like rusted nails and some times I can smell and taste it, I brush my teeth and use mouth wash two times a day, and some times three times a day. What could this mean, and should I be worried? I’m 45 by the way.

Hi my 9 month olds breath smells like sweet but stinky smelling poop n it just started about a day or two ago what do u think it could be

I hope your child is ok, as I see your question was posted in 2018. When my breath smelled like Poo, it was because my intestines had a bowel blockage. I had to have emergency surgery.

could need a brush and how sweet?my granddaughter is 9mo also x
patty lopez

My 2 yr old twin daughters but only ones breath smells like latex/acid since birth. No answers from the docs. No matter what she eats drinks or how many times she brushes. The smell is coming from within somewhere. Please help

Dorothy,
My breath smells like chocolate. I not should why breath smells like chocolate. Please help. I am 62 years old.

Floss your teeth everyday, and brush your tongue every time you brush your teeth.

Is he diabetic? If he hasn’t been diagnosed with diabetes, get him to have his glucose tolerance checked.

It could be ketoacidosis due to diabetes. Have him see a doc to check his glucose tolerance.

I’ve never heard of anything like that. What time of day do you smell it or is it there all the time?

Here my husband breath smells Like mustard and he didnt eat anything with mustard in it so can you tell me were it Come from tell me what to do so i can help him

he has to brush
patty lopez

I’ve never heard of anything like that. What time of day do you smell it or is it there all the time?

It might actually be vomit, if he’s been drinking beforehand.

What causes breath to smell like a skunk or diesel fluid?

My son’s breath smells like blood

probably tonsil stones. you can still get them without tonsils

look into lactose intolerancy and lactose overload. Similar smells, with different treatments and actual causes. My son gets lactose overload every so often and his breath smells of soured milk and poop smells of vinegar.

It sounds most like diabetic ketoacidosis.

My 5 1/2 month old son has had a peanut oil smell on his breath recently. It comes and goes every so often. I breastfeed and we have been introducing baby foods. I have not ingested, nor have we fed him with anything with nuts. He is not exibiting any other signs or symptoms. I am trying to research what it might mean, but I am not seeing anything other than articles coming up for peanut allergies and such. What could the odor mean?

I think you mean tongue not “tounge”

My breath smells like rubber, stinky feet, dead fish, and like something has rotten in my mouth. The same odor comes from my nose too. I had my tonsils removed in 2015 and my breath and nose still stinks. This is making me so depressed because when I see my Primary care docs or the ENT they also say they don’t smell anything. Suggested that I seek counseling.

probably tonsil stones. you can still get them without tonsils

Hi Connie,

Thanks for writing in.

“Oil pulling” has been used for a very long time. It’s very simple — place about 1/2 teaspoon of coconut oil in your mouth and swish it around for to to 20 minutes. Sometimes as little as five minutes will do the trick. When you’re done, spit the coconut oil into a disposable container (paper cups work well) and throw it away in the trash (not down the drain).

Typically for tonsil stones people do this a few times a day. It may take a week or so to see results. It is also hailed as a way to remove impurities.

I’ve done it myself, though I don’t have tonsil stones. It leaves my mouth feeling fresh and very silky.

I hope that helps enquiring minds ;)

Best, @MsGreene
Note: I am the co-founder of DrGreene.com, but I am not Dr. Greene and I am not a doctor. Please keep that in mind when reading my comments and replies.

Connie

I have been reading a lot of the posted questions and have now become curious….what is “oil pulling”? Enquiring minds just want to know.

Hi Connie,

Thanks for writing in.

“Oil pulling” has been used for a very long time. It’s very simple — place about 1/2 teaspoon of coconut oil in your mouth and swish it around for to to 20 minutes. Sometimes as little as five minutes will do the trick. When you’re done, spit the coconut oil into a disposable container (paper cups work well) and throw it away in the trash (not down the drain).

Typically for tonsil stones people do this a few times a day. It may take a week or so to see results. It is also hailed as a way to remove impurities.

I’ve done it myself, though I don’t have tonsil stones. It leaves my mouth feeling fresh and very silky.

I hope that helps enquiring minds ;)

Best, @MsGreene
Note: I am the co-founder of DrGreene.com, but I am not Dr. Greene and I am not a doctor. Please keep that in mind when reading my comments and replies.

my son is 21months old ad his breath started smelling like garlic this morniing. he was diagnosed with a brain tumor so we guess that tat is one of the effects of a brain tumor. could you maybe clarify if we need to see a gp asap

I took some antibiotics and startEd to get a smell of something like a green smell . What causes that.

Please don’t take antibiotics for bad breath. Antibiotics are more likely to cause you bad breath and all sorts of inbalance issues. They should only EVER be used for an emergency. Your issue has is possibly BECAUSE of the antibiotics.

If anyone wants some advice please reply.

I will be addressing health issues in my new channel ‘journey to health’ on youtube. Anyone is welcome to ask me anything there.

I took some antibiotics and startEd to get a smell of something like a green smell . What causes that.

My daughter is 3, and it just stared today. Her breathe smells like a metallic smell. Almost like blood tastes in the mouth. I looked all in her mouth and I see nothing. Should I be really concerned? Any help would be greatly appreciated.

I’m dating someone who’s breath smells of corn it is the worst :(

What causes me to smell and taste a musky smell all the time. Nasty

Check her blood sugar

That’s a serious intestinal issue. Maybe even a perforation

My husband’s breath at times smells like beef jerky. Even right after after brushing his teeth.

My breath smells like fish 🙃