A persistent, unpleasant odor that doesn’t go away with brushing or flossing may be due to an underlying medical condition, such as diabetes or gum disease.

Bad breath is common in the morning and after eating or drinking. It’s often a cue that you need to brush or floss your teeth right away. However, a persistent odor from your mouth, even after dental hygiene, may indicate an underlying medical condition.

Let’s discuss the symptoms of chronic bad breath, its causes, and its risk factors. We’ll also discuss how to get rid of chronic bad breath and when to speak with a medical professional.

You may not be able to perceive the smell of your breath, and it may be hard to pinpoint what bad breath smells like, especially as there are different types of bad breath. But, often, people around you can perceive it.

The major symptom of chronic bad breath is persistent, foul-smelling breath that’s often strong enough for others to notice.

If you have chronic bad breath, it may smell like:

  • partially digested food (sour)
  • fruits
  • acetone
  • ammonia or urine
  • old or decayed food
  • sulfur or rotten eggs
  • fish
  • poop

Bad breath, also called halitosis, is used to describe when an unpleasant odor is released from the mouth. While bad breath isn’t life threatening, you may be concerned if you have it.

Some medical conditions are potential causes of chronic bad breath.

Dry mouth

Dry mouth, also called xerostomia, can cause bad breath. This condition occurs when your salivary glands don’t produce enough saliva, causing dryness. Saliva helps to cleanse and wash away dead cells and food particles. But when there’s not enough of it, the particles may decompose, leading to bad breath.

Tonsil stones

Tonsil stones occur when debris like food, minerals, and bacteria get trapped in the tonsils — two masses of soft tissue at the back of your throat — causing them to harden and form lumps. The accumulated bacteria and other debris can cause bad breath.

Cavity or gum disease

Periodontal disease, or gum disease, is the infection and inflammation of the gums. It occurs when bacteria infect the gums. Bad breath that won’t go away is one of the early symptoms of periodontal disease.

Gastroesophageal reflux disease (GERD)

GERD is a chronic gastrointestinal condition that occurs when acid-containing contents of the stomach flow back into the esophagus. When stomach acid, undigested food, and bile get regurgitated, they can cause a strong sulfur-like smell that doesn’t go away.

Infections of your nose, throat, or lungs

Infections caused by a buildup of bacteria in the upper respiratory tract and airways can cause you to have foul-smelling breath. The infections can last for a short while or for a long time and may require medical treatment.

Liver disease or kidney disease

Your liver and kidneys help filter toxins out of your body. But impairment of these organs affects their ability to efficiently remove toxic substances from the body, which can lead to bad breath that doesn’t go away.

Using tobacco products

Tobacco smoking can increase the production of volatile sulfur compounds in diseased gums, causing bad breath.


Diabetes can cause increased glucose levels in the saliva. This can promote infection and bad breath. People with diabetes are at a higher risk of producing more ketones — chemicals produced when the body breaks down fat — and developing periodontal disease, which can both cause bad breath.

Peptic ulcer

While it‘s not common, bad breath can also be linked to peptic ulcers. This is because Helicobacter pylori,the bacteria that cause stomach ulcers, can also trigger bad breath.

Intestinal blockage

A blockage in the intestinal tract, which can be caused by surgeries or medical conditions such as a hernia, can make it hard for digested food and waste to move through the body. This can cause bad breath that smells like poop.

Medical treatment and at-home remedies can help you get rid of chronic bad breath.

Home remedies

Try the following at-home remedies to get rid of your bad breath:

Medical treatment

If chronic bad breath is caused by an underlying medical condition, a doctor will make a diagnosis and then prescribe medications to treat the condition. For instance, if you have diabetes, your treatment will focus on managing your blood glucose levels.

Along with treating the underlying cause, a doctor may also discuss with you how to practice good oral hygiene. They may suggest professional cleaning and the use of special mouth rinses to clear out bacteria in your mouth.

A review of several studies shows that about 31.8% of people have bad breath at some point.

If your bad breath persists even after trying at-home remedies, consider speaking with a medical professional.

If bad breath is accompanied by symptoms that affect your mouth, such as sores or gum pain, you should consider seeing a dentist.

Either doctors or dentists can diagnose and treat bad breath, depending on the cause. They may check your family and medical history while determining the diagnosis. They may also use tools to help find the source of the bad odor from the mouth and the possible cause. These include:

  • BANA test: This test measures the levels of the BANA enzyme, which is produced by bacteria and causes mouth odor.
  • Gas chromatography: This test measures methyl mercaptan, hydrogen sulfide, and dimethyl sulfide, which are volatile sulfur compounds produced after food breakdown by bacteria.
  • Ammonia breath analysis: This type of analysis detects ammonia in breath samples.
  • Beta-galactosidase test: This test measures the level of the enzyme beta-galactosidase, which has been linked to bad breath.

If a dentist doesn’t find any dental cause for bad breath, they may refer you to a doctor.

Practicing self-care routines, such as brushing and flossing regularly, eating balanced meals, and drinking enough water, can help prevent bad breath. Consider seeing a doctor or dentist if you experience bad breath that doesn’t go away.