Believe it or not, but certain prescribed medications — including those for high blood pressure, depression, nasal congestion, acne, asthma, obesity and more — can cause bad breath. The reason for this is that many medications come with the side effect of dry mouth, which Jon Marashi, DDS, California-based celebrity dentist, explains, can in turn cause bad breath. "Consulting with your physician about dosage and coming up with ways to counter attack dryness should help," he adds.

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If your diet is particularly heavy in protein, namely red meat, it might actually contribute to bad breath. "Since bad breath is caused by the breakdown of protein in your mouth, it can also be caused by an excess of a similar breakdown in your stomach that occurs when you eat a lot of protein," explains Dr. Baise. "As red meat contains more sulphur than any other protein source, it is particularly likely to cause bad breath, as more hydrogen sulphide is produced when it breaks down." This also explains the phenomenon of "keto breath," or bad breath that is associated with those who follow the ketogenic diet, which generally calls for high fats and low carbs.

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While this one might be quite obvious, it's more than worth a mention. "Not brushing or flossing your teeth and gums regularly causes the buildup of tiny food particles and bacteria in the mouth, which causes gums to become inflamed and red," explains Dr. Marashi. "This irritation can release a bad odor in the mouth signaling an infection, most likely periodontal gum disease." Visiting your dentist for a cleaning, coupled with regular brushing and flossing should help fight this.

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Oftentimes bad breath can be caused by bacterial growth or infections in your sinuses. If you have sinusitis, for example, a common condition that can be triggered by a cold or allergies, bad breath is likely to come as a side effect. "Post nasal drip in addition to sinusitis can especially cause bad breath as the encourage build-up of microbes, foreign objects and metabolites that cause bad breath," adds Tim Stirnman, DDS, dentist at Compassionate Dental Care in Lake in the Hills, Illinois. So get those sinus issues taken care of — and your bad breath might just clear up too.

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If you're not following the 8x8 rule (aka drinking eight 8-ounce glasses of water a day), you might be dehydrated — and this might be the cause of your bad breath. "The saliva in our mouth contains antibodies that can kill some of the bad breath causing bacteria," explains Dr. Baise. "When we are dehydrated our mouths still contain enough moisture to support bacterial growth, but not enough saliva to contain the antibodies necessary to halt this growth." Therefore dehydration can cause bad breath. Plus, there are plenty of other health reasons to stay hydrated, so drink up!

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