What Causes Bad Breath (Halitosis)? 17 Causes & Medical Solutions

Beers with the boys, a girls’ night out over wine, an after work happy hour. These are all a recipe for fun, but your partner may notice something less fun in the morning—your bad breath.

Unlike most liquids, alcohol dries your mouth out which aids bacteria to cause bad breath, also known medically as halitosis. Caffeinated beverages can do this too, and so can cigarettes and spicy food. This prevents your natural mouth-cleaning agent, saliva, from doing its job. When saliva’s not on patrol, bacteria thrive, leaving your mouth less than minty-fresh.

Sure, it just sits there holding your tongue in place most of the time. But the back of your tongue is also the spot where hard-to-reach bacteria tend to congregate. The bacteria in your throat, beneath your tongue and on the back of your tongue break down proteins inside your mouth. When they do, they release sulfur compounds that reek. These include hydrogen sulfide, the same compound that gives rotten eggs and natural gas their strong odor. Another top offender is methanethiol, which is released by paper mills and flatulence, and is also found in many plants and vegetables.

When bacteria gather, they tend to grow. The colonies of bacteria are in competition with neutral or nicer-smelling colonies. Some mouths have more of the offensive-smelling kind than others, and some scientists are looking into products that could kill off the stinky bacterial colonies and preserve the more pleasant ones. Until these products are available to consumers, though, brushing teeth, flossing, and tongue scrapers remain the best way to keep down bad breath-causing bacteria.

If you’re attempting a very-low-carb diet, you may get something else besides weight loss. Very-low-carb diets are ways to achieve ketosis, a natural process that forces your body to fuel the brain and other organs with stored fat rather than the usual carbs.

One of the more unsavory side-effects of ketosis is known as “keto-breath.” This process causes the body to emit certain chemicals called ketones, and when you exhale, these smell similar to acetone, the principle ingredient in nail polish remover.

If you’ve been low-carb dieting and notice a slightly sweet chemical smell coming from your mouth, forget asking your dentist for help, because this is one bad breath cause that can’t be overcome with better oral hygiene. Instead, you’ll need to either change your diet or mask the smell somehow. Mouthwash may be your best bet. You could try sugar-free gums or lozenges too, but be careful—even the sugar-free varieties often come loaded with carbs, which will throw off your weight-loss plan.

When your body fights off an infection, you may not have your breath on your mind at first. But that could be the first thing people close to you notice. Colds, sinus infections, and bronchitis are causes of bad breath.

This is trickier than it seems, though. Sometimes your sinuses are clogged without an infection, for instance when you have allergies. Mucus alone does not cause bad breath, as it is odorless. Some people have chronically stuffy noses, though, and this can cause halitosis. If you regularly breathe through your mouth, this dries the mouth out, leaving it free of saliva. And saliva is the mouth’s main cleaning agent, so going without it can make your breath smell bad.

In 80% to 90% of cases of bad breath, the mouth is the problem. Not when it comes to a certain ulcer-causing bacteria, however. One study found that among 18 patients with halitosis (the medical term for bad breath) who were also infected with the H. pylori bacteria, 16 were cured of their bad breath about a month after the bacteria was killed off. Not only that, but the patients were relieved of their other symptoms, such as nausea.

Does your medication dry your mouth out? If so, you’re not alone. More than 400 different drugs—both prescription medications and over-the-counter remedies—are known to inhibit saliva. Since saliva is your mouth’s natural cleaning agent, you may be depriving yourself of fresh, clean breath.

If you need to be on your medications, there are other solutions besides quitting them. Drinking frequent, small sips of water could be the right solution for you. Another possibility is to chew sugar-free gum. If these don’t work you can also talk to your dentist about the best oral rinses for your situation.

Have you ever found a small white ball coming from the back of your mouth? It’s firm, but if you squish it, it gives off a terrible smell. These little white globs are known as tonsil stones. They’re made up of hardened bacteria, along with the nutrients that feed these bacteria: namely, dead cells, mucus, and leftover food. Tonsil stones are normal and generally harmless, but they can contribute to bad breath.

As the name suggests, tonsil stones often get lodged along the ridges of your tonsils. They may also form on the back of the tongue, close to the throat. They often break free on their own, but if they’re bothering you there’s another trick that may work. Try gargling with salt water. If that doesn’t work and it continues to be a problem, talk to your dentist about other solutions.

Fruit is good for you, right? Well, yes, but dried fruit is loaded with sugar. Whether it is raisins, prunes, dried apricots or anything else, when fruit is dried the water is whisked away, leaving lots of sugar. And guess who besides humans loves sugar? That’s right—the bacteria that cause halitosis.

But wait, there’s more. Dried fruit is also sticky, and it tends to get stuck in hard-to-reach places within your mouth like between your teeth. All the while it is attracting bacteria. So if you like to snack on dried fruit, try brushing and flossing right afterwards.

If you have frequent, persistent heartburn, gastroesophageal reflux disease may be to blame. This condition, more commonly known as GERD, has also been associated with bad breath. In fact the more heartburn you have, the likelier you are to have bad breath according to one large study. GERD and halitosis are even more strongly linked in people who also wear dentures.

Why does GERD sometimes cause bad breath? Scientists think there could be a few reasons. One is that GERD can cause post-nasal drip, which is known to leave your breath reeking. Another possible reason is that with a malfunctioning esophagus, stomach gases can escape back up the throat, which can certainly be a stinky problem. GERD affects many people, and your doctor can help if this is the cause of your halitosis.

There’s a very good chance you have had a cavity. More than 90% of adults have had one, in fact, with the average cavities in an adult mouth being a little over three. Most of those cavities have been drilled and filled, but your oral problems may not end just because the cavity has been treated.

Dental fillings are like cracked teeth in that they offer a place for halitosis-causing bacteria to hide. They can also obscure tooth decay underneath, which is another popular breeding ground for such bacteria. When your dentures don’t fit well, they can cause the same type of problem. Mark it as another good reason to get your regular dental checkup.

We’ve already covered how dry mouth can leave your breath in terrible shape. Again, this is because saliva cleans the mouth and helps wash away the bacteria that leads to bad breath. But you may not know why your mouth is dry. Here are a few causes of dry mouth:

• Medications such as blood pressure medicine, painkillers, and antidepressants.
• Medical conditions such as Sjögren’s syndrome.
• Head and neck trauma.
• Smoking.

Consider whether one or more of these may be contributing to your dry mouth (known to doctors as xerostomia). If so, consider discussing it with your dentist, who can help resolve many of these problems.

It stands to reason that if you aren’t brushing regularly, your partner may smell it. Failing to take daily care of your teeth leaves the unpleasant odor of lingering bacteria, and it can lead to cavities which can also cause bad breath. The American Dental Association recommends you brush twice a day for two minutes each time using a soft-bristled brush, and floss daily.

You had to know this would be on the list somewhere. Everyone has woken up with morning breath, that unpleasant odor that visits your mouth after a good night’s sleep. There is a good reason behind this. Saliva production slows down while you sleep. It’s made worse when you breathe through your mouth while you sleep, or if you snore. Some medications can make it worse, too, which makes this problem especially aggressive among the elderly, who tend to be on several medications.

The solution to this is quite simple. The National Health Service in England suggests you brush right before bed without eating or drinking anything afterwards. To make sure you’re doing your all, be sure to brush your tongue as well.

This may seem obvious at first glance, but do you know why garlic and similar foods leave your breath in such an awful state? Besides that, why does garlic breath last so very long—even resisting the tooth brush? The answer to both questions comes down to sulfur.

Doctors discovered in the 1930s that garlic can cause bad breath without ever entering the mouth. A patient was fed garlic soup through a feeding tube and hours later, the patient’s breath wreaked of garlic. That’s because some of the compounds within garlic last a long time in the bloodstream, and they end up in your lungs when you exhale. It can also be sweated out.

Believe it or not, there’s an easy solution to garlic breath, provided you have some mint or an apple handy. Chewing on either mint or an apple can neutralize the chemical compounds in garlic. Other foods that help include milk, parsley, lemon juice, and green tea.

Sometimes oral health problems leave your breath reeking. And sometimes bad breath can be a clue that there are larger health problems that need addressing. When you have persistent bad breath, this is one symptom of gum disease. Other signs include bleeding gums that are red and swollen. A periodontist can help with various treatments that may include the use of ultrasound, radiography, and dental implants.

Cigarette smoking can lead to offensive mouth odors on several fronts. The first is the smell of burnt tobacco, which is commonly offensive to nonsmokers. The second is smoke’s tendency to dry the mouth, which leaves it without bacteria-cleansing saliva. Finally, cigarette smoking has been linked to gum disease, which is another source of bad breath.

Quitting smoking is infamously challenging, but enormously beneficial to your health. If you don’t smoke, don’t start. And if you do, talk to your doctor about effective strategies for quitting.

Dentures are not that different from natural teeth when it comes to cleaning. Both need to be cleaned every day to avoid halitosis and other health concerns. Dentures should be brushed just like teeth—and don’t neglect the soft tissue in your mouth, too, such as the tongue and the roof of your mouth.

You’ll need to take one extra step to ensure pleasant breath if you wear dentures, though. That extra step is to remember to remove them at night by placing them in a glass of water. The water is important—without it, your dentures can warp, and ill-fitting dentures are liable to leave spaces for odorous bacteria to collect and grow.