Bad breath, or halitosis, can put a damper on everything from a friendly conversation to a job interview or kiss—especially when you can’t figure out why you have it. “The entire cause of bad breath really comes down to an overgrowth of bad bacteria in your mouth,” says Michael Apa, DDS, of Rosenthal Apa Group in New York City. So what causes the bacteria? Though garlic gets a bad rap, it’s not the only culprit. Here, some likely reasons for that unwelcome oral odor:

  • Tongue Bacteria: Dr. Apa says that tongue bacteria is responsible for more than 85% of bad breath. The tongue’s uneven surface makes it easy for bacteria to get trapped and linger, according to Mayo Clinic.
  • Bad Gums & Gum Inflammation: Apa also notes that bad or inflamed gums are top culprits. Indeed, per Mayo Clinic, when plaque builds up on your teeth (often the result of neglecting to brush and floss regularly), it can irritate your gums and create plaque-filled pockets between them and your teeth.
  • Dry Mouth: The bacteria that builds up to cause bad breath is often a result of dry mouth. “When saliva is not produced, bad bacteria takes over and causes bad breath,” Dr. Apa says. We naturally get dry mouth when we sleep (especially if it’s with an open mouth), so your morning breath probably isn’t a result of forgetting to brush your teeth last night.
  • Dentistry Work: In some cases, things like ill-fitting crows or faulty veneers can cause bacteria to build up, says Dr. Apa. Post-oral surgery wounds in your mouth, from things like tooth removal, can also be a contributing factor, according to Mayo Clinic.
  • Alcohol: “Part of it has to do with alcohol drying out your mouth, but part of it also has to do with the strong smell that some liquors leave behind,” Dr. Apa says. “As with coffee, try to rinse and keep your mouth moist to limit the effects that alcohol will have on your breath.”
  • Tobacco: Not only are smokers and oral tobacco users more likely to have bad breath from the products’ own odors, but according to Mayo Clinic, they’re also more prone to gum disease, which is another source of oral odor.
  • Food: It’s no secret that eating certain foods, like onions and strong spices can leave an unwelcome odor. But the result is milder for some foods than others, like the infamous garlic. “Garlic is a whole different animal,” says Dr. Apa. “It gets into the skin and bloodstream and emits that odor through your food and saliva.” Want to freshen up? Just brush and floss, or chew gum if you’re in a pinch. “There’s little evidence that food such as parsley will mask the sauerkraut-laden hotdog we just ate,” says Dr. Apa.

So what can you do to curb the smell? To start, be vigilant with your daily oral care. Dr. Apa advises us to floss, mouth rinse, and brush (for two minutes, with an electronic toothbrush) twice a day. And check the ingredients on your toothpaste and mouthwash. “It’s best to use a paste that contains potassium nitrate, recaldent, amorphous calcium phosphate, or heavy doses of fluoride,” Dr. Apa says. As for mouthwash, ditch the alcohol and save it for your nights out. “Alcohol can actually aggravate your gums and cause irritation that will further expose the cementum layer [the surface layer of the tooth root].” It also further dries out your mouth, and kills too much bacteria, including the good kinds. Instead, Dr. Apa says to The best look for a rinse with a high-fluoride content.

Outside of your regular dental routine, Dr. Apa has a few treatment suggestions:

  • Pilocarpine: If you’re suffering from halitosis, try this medication that’s been used to treat dry mouth. “Originally obtainable in pill form, pilocarpine is now available in over-the-counter mouth washes for the truly afflicted,” says Dr. Apa.
  • Gum Chewing: This simple solution really does work. “The act of chewing stimulates salivary glands and increases saliva, taking care of dry mouth and rinsing away the dry breath,” Dr. Apa says. Look for gums that contain xylitol (Dr. Apa notes most of them do nowadays), an ingredient that fights cavities.
  • Tongue Cleaners: Not a gum fan? Tongue cleaners, which you can get at most drug stores, can remove that pesky tongue bacteria and help prevent both bad breath and gum disease.

As for what not to do, avoid breath strips. “Breath strips dissolve through alcohol, and alcohol will dry out your mouth,” says Dr. Apa. The initial pop of a breath strip will give you a minty feel, but the last thing will be dry mouth bringing back bad breath faster.”

If you find that none of these treatments are helping, there might be something else going on. In some cases, Dr. Apa says that chronic bad breath—especially a salty, sour taste in your mouth—could be an indicator of more serious conditions, like gum disease, improper dental restoration, tooth decay, stomach problems, or even respiratory tract infections. If your bad breath seems unyielding, check in with your dentist—but don’t wait for there to be a problem to schedule a visit. Even if everything seems fine, it’s important to schedule regular checkups.