Health Topic

Bad Breath

There are many reasons why you might have bad breath (also known as halitosis) including a lack of dental hygiene. Learn about how you can prevent it.

Reviewed Reviewed by a registered pharmacistGeneral information

Also called: Halitosis

Important: This page is general information, not medical advice. It does not recommend or prescribe any treatment. Always consult your doctor or pharmacist before starting, stopping or changing any medicine.

About Bad Breath

There are many reasons why you might have bad breath. You can get it if you don't brush and floss regularly. Bacteria that build up in your mouth and between your teeth produce the bad odor. Other problems in your mouth, such as gum disease, dry mouth, or cavities, may also cause it. Sinusitis or problems with your nose may be to blame. You can also have bad breath if you eat some foods, like raw onions, garlic, or cabbage. And of course smoking causes its own bad smell. Some diseases and medicines can cause a specific breath odor.

Having good dental habits, like brushing and flossing regularly, help fight bad breath. Mouthwashes, mints or chewing gum may make your breath fresher. If you have a disease that causes the bad breath, treating the disease may help give you fresher breath.

It sits within Mouth and Teeth and Symptoms.

The lead U.S. institute for this subject is the National Institute of Dental and Craniofacial Research.

When to speak to someone. Reading about a topic cannot tell you whether it applies to you. Speak to a doctor or pharmacist if symptoms are severe, sudden, getting worse, or simply not going away — and seek emergency care immediately for chest pain, breathing difficulty, sudden weakness or confusion, or a serious allergic reaction.

Research on Bad Breath

93 studies areregistered for this condition on ClinicalTrials.gov, the U.S. National Library of Medicine's public registry. A selection is below — the links go straight to the registry entry, not to a summary of ours.

What a registered study does and does not mean. Registration means a study exists and has been declared publicly. It says nothing about whether the treatment being tested works, is safe, or is available to you. Many studies find no benefit — that is what research is for. Never seek out an experimental treatment on the strength of a registry entry alone.

Research currently under way

Research already completed

Study data from ClinicalTrials.gov, a service of the U.S. National Library of Medicine. Retrieved 2026-07-30. Registry entries are supplied by study sponsors and investigators; ClinicalTrials.gov does not verify their scientific validity. PocketsInfo is not affiliated with, and not endorsed by, the NLM or the NIH.

Where to read more

Rather than paraphrase, we point you to the primary sources. Every link below is to a government health agency, a national institute or a recognised medical body — grouped by what you are trying to find out.

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Treatments and Therapies

Clinical Trials

Medical subject headings

Clinicians and researchers index this subject under Halitosis. These are the terms to use when searching medical literature.

This page is built from the MedlinePlus health topic record for Bad Breath, a service of the U.S. National Library of Medicine (NLM), National Institutes of Health. Information is from MedlinePlus.gov. PocketsInfo is not affiliated with, and is not endorsed by, the NLM or the NIH. Retrieved 30 July 2026.