Do people back up in horror when you open your mouth? If you had garlic and onion pizza for lunch, you know to keep the breath mints handy. But if your halitosis is a regular occurrence, there are plenty of other things that might be causing your bad breath.

Here are a dozen reasons your breath might be bad and some solutions that can make things better.


There are particular foods — such as raw onions, garlic, cabbage and some spices — that signal "keep away!" After your body digests them, they make their way from your bloodstream to your lungs and impact the way your breath smells. To keep your breath as fresh as roses, avoid foods that trigger mouth odors.

Poor oral hygiene

Bad breath is often caused by bacteria that grow in your mouth. When food breaks down, those tiny particles can stay in your mouth and cause more bacteria — especially if you don't brush and floss often enough. They form plaque, a sticky layer of bacteria on your teeth. Brush at least twice a day — especially after you eat. Floss daily too. Your dentist can recommend a mouth rinse or toothpaste to help fight bacteria and plaque buildup.


Similarly, dentures or other oral appliances that aren't cleaned well or that don't fit properly can offer a comfortable home for food particles and bacteria that cause odors and bad breath. Make sure you keep appliances clean and have them checked regularly for proper fit.

Cavities and other mouth issues

Whenever you have problems in your mouth, including cavities, abscessed teeth, gum disease or mouth sores, bacteria can thrive and trigger bad breath. See your dentist regularly to make sure you don't have any underlying issues.

Dry mouth

Saliva helps clean your mouth, washing away dead cells and neutralizing acids. When these cells remain or acids aren't neutralize, the result can be bad breath. Dry mouth occurs naturally when you sleep, but it can be even worse if you sleep with your mouth open. It can also be a side effect of some medications, diseases and salivary gland problems. To avoid dry mouth, drink lots of water and chew sugarless gum or suck on sugarless candy. If your problem is chronic, your doctor or dentist may be able to prescribe medicine that stimulates saliva flow.

Stuck object

This is more of a kid thing, but when something gets lodged up in the nose (a LEGO? A pea?), it can cause a smelly discharge and resulting bad breath.  


In some people who have gastroesophageal reflux disease, food lingers in the stomach and starts to decay there, triggering bad breath. Or sometimes people with GERD may regurgitate tiny bits of undigested food, which can also cause bad breath. If you suspect GERD, see your doctor for treatment.


Some drugs, like antidepressants, diuretics and aspirin, can affect bad breath by contributing to dry mouth. Drink plenty of water with medications and chew sugarless gum or suck on sugarless candy to fight dry mouth.

Respiratory tract infections

Bronchitis, sinusitis, pneumonia and other respiratory tract infections break down tissue, triggering the flow of mucus and cells that feed odor-causing bacteria. Even postnasal drip can lead to bad breath. If this is a long-term problem, see your doctor for treatment.

Tobacco products

Smoking or chewing tobacco causes its own unique brand of smelly breath. In addition, tobacco particles can lodge in your teeth, contributing to bacteria growth. People who use tobacco are also more prone to gum disease, which is another source of bad breath. Hint: Stop using tobacco!

Other diseases

Strong-smelling breath can be a sign of specific diseases such as diabetes, liver or kidney problems. It may also come from problems with tonsils. See your doctor to rule out any underlying medical issues that may be contributing to mouth odors.


Drinking a lot of alcohol can dry your mouth, contributing to bad breath. Cut back on your drinking or stock up on the breath mints.

Related on MNN:

Mary Jo DiLonardo covers a wide range of topics focused on nature, health, science and anything that helps make the world a better place.

12 reasons you might have bad breath
From stinky foods to disease, there could be all kinds of causes for your halitosis.