Bad Breath: Causes, Symptoms, and Treatment
Medically reviewed by Achuta Uppu, MD, Internal Medicine. Last reviewed: October 23, 2026.
What kind of doctor treats Bad Breath?
A dentist treats most bad breath, because the smell usually starts inside the mouth. A primary care doctor can help when the mouth is healthy but the odor keeps coming back. A direct primary care or concierge doctor can be a first stop for an evaluation and can refer you to a specialist when needed.
What is bad breath?
Bad breath, also called halitosis, is a common problem. Studies show that 50 percent of adults have had it at some point in their lives. There are many reasons why your breath might smell bad. While many causes are harmless, bad breath can sometimes be a sign of something more serious.
Symptoms
The main sign is an unpleasant smell that others can notice when you speak or breathe. You may not notice it yourself. A constant bad taste in your mouth can go along with it.
Causes and who gets it
The most common cause is bacteria that build up in your mouth and between your teeth. These germs feed on food left in your mouth and leave a foul-smelling waste product behind. You can get bad breath if you don't brush and floss regularly. Other causes include:
- Mouth problems such as gum disease, dry mouth, or cavities.
- Dry mouth, which can come from certain medications, salivary gland problems, or simply breathing through your mouth. Saliva works around the clock to wash out your mouth, so too little of it leaves more germs behind.
- Foods such as garlic, onions, or cabbage, which affect the air you exhale.
- Smoking and tobacco, which cause their own bad smell. Tobacco users are also more likely to suffer from gum disease. Since smoking affects your sense of smell, smokers may not be aware of how their breath smells.
- Certain medicines, which can cause a specific breath odor.
- Other conditions, such as a sinus condition, gastric reflux (stomach acid coming back up), diabetes, liver or kidney disease. Mouth infections can cause bad breath too.
How doctors diagnose it
A dentist examines your mouth and looks for gum disease or dry mouth. Regular checkups let the dentist find these problems before they become more serious. If your dentist rules out mouth causes and you brush and floss every day, the odor could come from another problem. In that case, your dentist may refer you to your primary care doctor.
Treatment
Good dental habits help fight bad breath. Brush twice a day and clean between your teeth daily with floss. This gets rid of the bacteria causing the odor.
- Over-the-counter mouthwashes can help kill bacteria or neutralize bad breath. They are only a temporary solution, so keep brushing and flossing.
- To get more saliva moving, eat healthy foods that require a lot of chewing, like carrots or apples. Chewing sugar-free gum or sucking on sugar-free candies also helps.
- If you wear removable dentures, take them out at night and clean them thoroughly before wearing them again.
- If you smoke or use tobacco, giving up this habit is good for your body in many ways, and not only for your breath.
If you have a disease that causes the bad breath, treating the disease may help give you fresher breath.
When to see a doctor
Bad breath that just won't go away, or a constant bad taste in your mouth, can be a warning sign of advanced gum disease. See your dentist right away. If your dentist rules out mouth causes and you brush and floss every day, your bad breath could be the result of another problem, such as a sinus condition, gastric reflux, diabetes, liver or kidney disease. In this case, see your healthcare provider.
How a direct primary care or concierge doctor fits in
A direct primary care doctor charges a flat monthly fee instead of billing insurance, while a concierge doctor usually charges more and often works alongside insurance. This doctor can check whether a condition such as diabetes, reflux, or sinus disease is behind the smell. The doctor can also work with your dentist and refer you to a specialist when needed.
Common questions
What causes bad breath?
Bacteria that build up in your mouth and between your teeth produce the bad odor. Gum disease, dry mouth, cavities, certain foods, smoking, some medicines, and some other conditions can also cause it.
How common is bad breath?
Studies show that 50 percent of adults have had bad breath, or halitosis, at some point in their lives.
Can mouthwash fix bad breath?
Only for a short time. Over-the-counter mouthwashes can help kill bacteria or neutralize and temporarily mask bad breath. It's only a temporary solution, however. The longer you wait to brush and floss away food in your mouth, the more likely your breath will offend.
When should I see someone other than a dentist?
If your dentist has ruled out other causes and you brush and floss every day, your bad breath could be the result of another problem, such as a sinus condition, gastric reflux, diabetes, liver or kidney disease. In this case, see your primary care doctor.
Sources
Medical Disclaimer
This content is for general educational and informational purposes only and is not medical advice. It is not a substitute for professional medical advice, diagnosis, or treatment, and reading it does not create a doctor-patient relationship. Always seek the advice of your physician or another qualified health provider with any questions about a medical condition, and never disregard or delay seeking professional advice because of something you read here. If you think you may have a medical emergency, call 911 (or your local emergency number) immediately.
