You may be walking around with it and not know. Your friends may be afraid to tell you. You may belong to the more than 50% of the general population that has halitosis, or bad breath. While it’s a common problem, it can be a social and emotional burden.

Why Does My Breath Smell? Unexpected Reasons

While poor oral hygiene is a common culprit for bad breath, there are other lesser-known factors that can contribute to this unpleasant condition.

Tonsil Stones

“Your tonsils are on the frontline of fighting infection,” says Dr. Butler. “If you’ve ever had an infection or virus, you’ve maybe also noticed swelling in your tonsils.”

Your tonsils detect bacteria and viruses and can engorge with white blood cells and antibodies to help fight foreign bodies. Food and drink must also go past your tonsils and can sometimes calcify into them, resulting in tonsil stones. These can cause bad breath.

Some people are more prone to tonsil stones than others. Tonsil stones are usually harmless and often disappear on their own, but if they become problematic, see an ear, nose and throat specialist.

Sinusitis and Postnasal Drip

Always clearing your throat? That could be a sign of postnasal drip, which is an excessive secretion of mucus from your sinuses that could be contributing to bad breath. Sinusitis, or inflammation of the sinuses caused by bacteria or a virus, can cause postnasal drip and bad breath as well.

Food and Drink

Sure, you’ve needed a piece of gum after eating a meal that’s heavy on garlic or onions, but your diet and drink choices can have a longer-lasting impact on the smell of your breath. In fact, many people on the keto diet report halitosis. This is because when your body is in ketosis, burning fatty acids instead of carbohydrates for energy, you release acetone, which has a sweet, fruity odor.

“Caffeine and alcohol can also contribute to bad breath by reducing your saliva production,” says Dr. Butler. “Saliva helps kill bacteria and eliminates excess food particles in your mouth.”

Gastroesophageal Reflux Disease (GERD)

GERD occurs when the muscle ring at the base of the esophagus does not properly function, allowing the contents of the stomach to rise into the esophagus. GERD has been linked to bad breath and can be treated in a variety of ways, from lifestyle changes to medications.

Dry Mouth

Dry mouth (xerostomia) is also associated with halitosis. When your mouth doesn’t make enough saliva, your mouth can’t clean itself. It can’t remove debris and particles left behind by food. Dry mouth is commonly caused by:

• Certain medications, such as antihistamines, decongestants and antidepressants
• Dehydration
• Tobacco use
• Beverages with caffeine or alcohol
• Spicy or dry foods
• Mouth breathing

“People with sleep apnea are at increased risk for bad breath,” says Dr. Butler. “Sleep apnea can cause people to breathe through their mouths during sleep. That leads to dry mouth and, in turn, bad breath.”

Nose Obstruction

A less common cause of bad breath can be a foreign object, like a green pea or bead, stuck in the nasal passage. “This is more common in younger children as they are more likely to put an object where it doesn’t belong, like their nose,” explains Dr. Butler. “They may be copying other children doing the same thing.”

She says that the two most common symptoms of a foreign object in the nose are unilateral nasal drainage on the side containing the object and foul breath odor.

“Occasionally a child may have a bloody nose or a whistling sound while breathing,” she adds. “If you notice a young child with unexplained bad breath or one-sided nasal drainage, have them evaluated by their physician for a possible foreign body.”

How to Combat Bad Breath

“Good oral hygiene is the best defense against bacteria build-up in the mouth,” says Dr. Butler. She offers these tips for mouth maintenance:

• Brush and floss: The American Dental Association recommends brushing your teeth with a fluoride toothpaste for at least two minutes, twice a day and flossing once a day to remove plaque and bacteria.
• Clean your tongue: Don’t forget to brush your tongue while brushing your teeth. “The tongue has many crevices that provide a favorable environment for the growth of odor-causing bacteria,” says Dr. Butler.
• Use mouthwash: Gargle with an alcohol-free antibacterial mouthwash after meals.
• Hydrate: Drinking plenty of water throughout the day keeps your mouth moist and helps flush out debris.
• Chew sugar-free gum: This can help increase your saliva production.

“Bad breath is largely a lifestyle concern,” says Dr. Butler. “If good oral hygiene isn’t remedying it, and you are finding that your breath odor is inhibiting you from living your life fully and confidently, see a physician to determine its underlying cause and your subsequent treatment options.”

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