12 Things Your Bad Breath Is Trying to Tell You

Updated: May 04, 2021

Got dragon breath (again)? Here's what your halitosis could mean for your health.

Woman in a pink shirt drinking a glass of water.
iStock/Anna Bryukhanova

You’re dehydrated

Dehydration is one of the causes of bad breath, according to the American College of Cardiology. Not drinking enough water means food (and the bacteria that feed on it) hangs out in your mouth longer, breeding and heightening the stench. Fortunately, the fix is as simple as the problem: Drink up! Plain H2O is best, but doctors add that sugar-free gum or candies can also help stimulate saliva flow.

Woman doctor talking to a male patient at the doctor's office.

You have a serious illness

The presence of certain, ahem, gasses in your mouth can indicate serious diseases that are also bad breath causes. For instance, excess methylamine may signal liver and kidney disease, ammonia may be a sign of renal failure, elevated levels of ketones can indicate diabetes, and nitric oxide levels can be used to diagnose asthma, according to a study in the journal Optics Express. (Rarely, it can also be a sign of certain oral cancers, too, according to the American Cancer Society). You can’t tell just from a sniff test, but if you have chronic bad breath, you might want to talk to your doctor about it. These are the 13 silent signs of oral cancer you should never ignore.

Elite athlete cyclist biking on a road.

You’re exercising outdoors too much

Elite athletes may have a higher proportion of breathing problems than the average population, according to a study published by the European Respiratory Society. Of people who exercised outdoors, about one in ten experienced some type of breathing problem like asthma, wheezing, and dry mouth, with cyclists being the most affected―nearly 50 percent! The problem, according to the researchers, is the outdoor air, one of the more surprising bad breath causes. While a breath of fresh air is certainly good for you, too much cold air in the winter dries out your mouth, and in warmer months, pollen and pollution wreak havoc. The end result can be bad breath related to allergies, nasal drainage, or chronic dry mouth. This doesn’t mean you should quit exercising—far from it!—but rather that you might want to limit your time exercising outdoors when it’s very cold, during allergy season, or in polluted areas.

Woman at the dentist's office getting her teeth cleaned.

You’re at risk for heart disease

Gum disease is associated with an increased risk of heart disease, according to the Mayo Clinic. And one of the major signs of gum disease is bad breath. Treat your gum disease and not only do you ditch the noxious mouth fumes, but you may also improve your heart health. Don’t miss these 10 early signs of gum disease you’re probably ignoring.

Doctor checking a woman patient's tonsils.

You have tonsillitis

One of the hallmarks of sore-throat disease is persistent bad breath. The same bacteria that give you bad breath are the ones that also infect your tonsils, giving you recurrent sore throats. Tonsillectomy, a surgery that removes the two glands in the back of your throat, can help treat the sickness and bad breath. Here are 9 things your bad breath says about your health.

Pregnant woman drinking a glass of water.

You’re at risk for pre-term delivery

Pregnant women need to pay particular attention to bad breath, according to the American Academy of Periodontology. Women with gum disease—often signified by halitosis—are more likely to have premature or low birth weight babies. This is why it’s so important to stay on top of your dental hygiene and checkups when you’re expecting, the group says.

Man lying on his side on the couch with stomach pain.

You have a stomach ulcer

When you think of ulcers you probably think of terrible stomach pain, problems eating and heartburn. But you may be overlooking another common symptom of the malady: bad breath. Helicobacter pylori, the bacteria known to cause stomach ulcers and also responsible for a large proportion of gastric cancers, can also make your mouth mega malodorous, according to the National Cancer Institute. Here are 9 more things bad breath can reveal about your health.

Overweight woman buttoning her pants.

You’re overweight

You can now add bad breath to the list of health problems caused by being overweight, according to a study published in the Annals of Medicine and Surgery. The researchers found that the more overweight a person is, the more likely their breath will smell unpleasant to others. They’re still investigating why this is the case. It may have to do with biological dysfunction or it may be another example of the social stigma endured by the obese.

Man eating a bowl of yogurt and fruit with a spoon.

You need to eat more yogurt

Bad breath, or halitosis, is caused by an overgrowth of “bad” bacteria in your mouth. But do you know what else is packed with bacteria? Yogurt! The humble dairy snack is a microbial superhero that can help fight off the stinky germs in your mouth and replace them with breath-friendly bugs. Eating yogurt daily for eight weeks reduced the amount of hydrogen sulfide and other stinky bacteria by 80 percent, according to a study published by the International & American Association For Dental Research. Here are 7 surprising foods that give you seriously bad breath.

Green candy breath mints in rows.

You need to pop fewer mints

Breath mints may promise fresher breath but that promise is fleeting, according to research from the American Chemical Society. That minty fresh scent is likely only masking the underlying odor problem and, even worse, the sugar in regular mints can feed stinky bacteria, making your problem worse. Skip the mints and focus on brushing and flossing, the researchers say. If you must indulge, a few ingredients like xylitol and magnolia tree bark have been shown to kill bad bacteria, so look for sugar-free products containing those. Plus, check out these 8 foods that will freshen your breath almost instantly.

Person pouring mouthwash into the lid.

You’re OD’ing on the mouthwash

Mouthwash is another product marketed to reduce bad breath that may actually make the problem worse. Most mouthwashes temporarily destroy bacteria—which may sound great until you realize they’re getting rid of all your oral bacteria. As your mouth repopulates you’re at risk for a bad bacteria overgrowth, according to experts. Plus the alcohol in mouthwash can dry out your mouth, another of our bad breath causes. Lastly, many people use mouthwash to mask poor dental care.


You need to brush and floss more

Okay, so this isn’t the most surprising thing on this list, but bad dental hygiene is the most likely reason behind your bad breath. “Halitosis is often the first sign of poor oral hygiene that may eventually lead to further periodontal problems,” said Walter A. Bretz, DDS, PhD, an adjunct associate professor in the department of cariology and comprehensive care at New York University College of Dentistry and the lead author of a large-scale study on the subject. “A good way to prevent periodontal disease and tooth decay is through at-home oral hygiene care and routine dental visits.” So make sure you’re brushing and flossing daily. Don’t miss these 13 other secrets your dentist wishes you knew.