With acid reflux, stomach acid leaks up into the esophagus. This can cause heartburn. The backward flow of undigested food, acid, and bile into the esophagus can also cause halitosis, the medical term for “bad breath.”

Up to 90% of halitosis occurs due to problems originating in the mouth. However, in some cases, issues arising in other areas of the body, such as acid reflux, can cause halitosis.

Chronic acid reflux, also called gastroesophageal reflux disease (GERD), leads to regular regurgitation of stomach contents into the esophagus. Many people with GERD report having halitosis. Research suggests treatment of GERD can significantly reduce this symptom.

This article looks at how to tell whether acid reflux may be the cause of “bad breath”, how it may cause halitosis, and home remedies and treatments for halitosis from acid reflux. It also looks at some quick tips that may help with having fresher breath.

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Oral issues are the most common cause of halitosis. A person experiencing this symptom may want to visit a dentist to rule out problems in the mouth.

The most common causes of halitosis include:

  • Tongue coating: A person may notice a white coating on their tongue, which could be due to various causes, including dry mouth.
  • Poor oral hygiene: It is best for people to brush their teeth twice a day with fluoride toothpaste and visit a dentist annually.
  • Mouth ulcers: These are painful sores in the mouth.
  • Gum disease or infection: A person may experience inflammatory disease that affects gum tissue.
  • Dry mouth: This symptom has several potential causes.
  • Faulty dentures: Dentures that are broken or do not fit correctly may cause halitosis.
  • Cavities: These are areas of tooth decay.
  • Gingivitis: People with this condition experience inflammation of the gums.
  • Salivary gland problems: A person may salivate too much or not enough.
  • Oral cancer: A person may develop mouth cancer in the lips, gums, tongue, or tissue of the inner cheeks.

If a person can rule out oral causes of halitosis and regularly experiences acid reflux, GERD may be causing their halitosis.

Research has found that while halitosis is a common symptom in people with GERD, their halitosis may not originate from an oral cause.

One 2022 study found that while 66% of the participants with GERD reported having halitosis, there was no association with oral factors. The researchers concluded that there is a relationship between GERD and halitosis and that the cause of halitosis in people with GERD may not originate in the mouth.

Learn more about halitosis.

When a person has acid reflux, stomach contents such as bile, undigested food, and stomach acid can flow upward into the esophagus. The presence of these contents can cause a person’s breath to smell.

Acid reflux can also cause inflammation and damage to the esophagus, which may lead to ulcers and infection. These can cause halitosis.

GERD can also cause corrosion of the thin mucous membrane that lines the esophagus. Researchers found that this can lead to an increase in bacteria called volatile sulfur compounds (VSC), which are the leading cause of halitosis.

A person with GERD may have an excess of these bacteria even if their oral health and hygiene are otherwise good.

Besides maintaining good oral hygiene, the following home remedies may be effective for halitosis:

  • Hydration: Avoiding dehydration by drinking plenty of water can help prevent dry mouth.
  • Cinnamon oil: Oral hygiene products containing cinnamon oil may help reduce VSC levels.
  • Green tea: Green tea may help reduce levels of bacteria that cause halitosis.
  • Probiotics: Taking oral probiotics may help improve oral health.
  • Tea tree oil: Rinsing the mouth with a diluted tea tree oil solution may treat halitosis as effectively as a common antimicrobial mouthwash ingredient.

Read more about home remedies for halitosis.

Medical treatments for acid reflux include:

Learn more about how to stop acid reflux.

A person can ease acid reflux at home, which may help improve halitosis. This may involve doing the following:

Read about home remedies and lifestyle tips for reducing acid reflux.

A person may be able to address halitosis in the short term by:

  • using antibacterial mouthwash
  • brushing the teeth, gums, and tongue
  • gently cleaning the tongue with a tongue scraper
  • using sugar-free gum or mints
  • drinking water and swirling it around the mouth
  • avoiding smoking
  • avoiding strong-smelling foods and drinks

Acid reflux can lead to halitosis, especially in people with gastroesophageal reflux disease (GERD). GERD may lead to halitosis due to strong-smelling stomach contents leaking back up the esophagus.

Acid reflux may also damage and inflame the esophagus, causing ulcers and infection and increasing bacteria called volatile sulfur compounds. These may all lead to halitosis.

A person can treat GERD-related halitosis by treating acid reflux. This can involve OTC and prescription medication and, in severe cases, surgery.

A person may be able to improve halitosis by practicing good oral hygiene, staying hydrated, and avoiding smoking and strong-smelling food and drinks.