Bad breath: Discover the cause to get rid of it for good

bad breath
Occasional bad breath is nothing to worry about. Most of us have experienced it at some point. However, chronic, persistent, and long-lasting bad breath is a real cause for concern. It can affect your professional and social life and be a source of anxiety.

Understanding and identifying the cause is the first step in dealing with it. Although oral conditions are the most common factors, other habits and underlying general diseases can also be involved.

In this article, you will learn about the different forms of bad breath, how it occurs, the possible causes, and treatment options to get rid of it for good.

Understanding halitosis or the bad breath issue:

the different causes of bad breath
Bad breath is not a disease or condition in itself. It is a symptom of an underlying problem.

Most forms of bad breath come from the mouth. In this case, bacteria break down proteins from food particles, residues, and saliva to produce malodorous substances called volatile sulfur compounds (VSCs).

Under healthy conditions, these bacteria live in harmony in our mouths without causing any harm. However, certain factors can cause them to multiply and overproduce VSCs.

Aside from the mouth, bad breath can originate from various sources. These include:

  1. Foods and drinks: Consuming items like garlic, onions, and alcohol can lead to bad breath after digestion. This unpleasant odor can linger for hours, with garlic being notorious for up to 72 hours!

  2. Fasting or low-carb diets: These diets can contribute to bad breath by increasing the breakdown of fats and proteins in the body. Additionally, reduced saliva production during fasting can encourage the growth of bacteria, leading to breath odor.

  3. Medical conditions: Certain health conditions can cause bad breath within the mouth. Examples include diabetes, kidney, and liver disease, and gastrointestinal issues that result in acid reflux.

  4. Medications: Some medications can release substances that produce foul smells and reduce saliva production. Antidepressants, antipsychotics, diuretics, and blood pressure medications are among the culprits.

  5. Pseudohalitosis or halitophobia: This less common form of bad breath is characterized by perceiving a foul smell in the mouth, even when the breath is normal. It is a result of extreme anxiety and excessive concern about dental health and hygiene products.


The nature and type of bad breath can be an indicator of the underlying condition:

  1. Fruity or Sweet Odor: Uncontrolled diabetes.
  2. Ammonia-like Odor: Kidney problems.
  3. Fishy Odor: Trimethylaminuria (fish odor syndrome).
  4. Sour or Acidic Odor: Acid reflux or GERD.
  5. Rotten Egg Smell: Poor oral hygiene or bacterial breakdown of proteins.
  6. Fecal Odor: Gastrointestinal issues, such as obstruction, constipation, or infection.
  7. Putrid or Foul Odor: Respiratory infections or lung conditions like bronchitis or lung abscess.

The common causes of bad breath

90% of bad breath comes from the mouth. Most of the bacteria involved are anaerobic, which means they need an oxygen-free environment to grow and release their malodorous compounds (VSCs).

In the mouth, we find them mainly in confined, oxygen-deficient areas, such as between the papillae of the tongue and inside the gum line. The most common factors that increase bad breath include:

  • Tongue coating: This is a thick, soft film filled with bacteria, dead cells, and debris that builds up on the tongue. It is the main source of VSCs in the mouth, accounting for 60-70% of the total.

  • Gum diseases: This is an inflammatory condition that affects the gums and surrounding tooth tissues, including the bone. In advanced stages, it can cause the space between the teeth and gums to widen, resulting in periodontal pockets.
    These pockets are the perfect environment for anaerobic bacteria to grow and release toxins. Therefore, the more periodontal pockets you have, the more CSVs you have in your mouth.

  • Cavities: Tooth decay or cavities are infectious diseases caused by bacteria. Bacteria convert the sugars in the food we eat into acid and gradually eat away at the tooth's enamel and dentin. They leave behind dead tissue and attract plaque and food particles, causing bad breath.

  • Dry mouth: This is caused by a lack of saliva in the mouth. Saliva is the mouth's natural cleaner and lubricant. When its production decreases, bacterial plaque builds up, leading to bad breath. A dry mouth can also predispose you to other oral conditions, including tooth decay and gum disease.

  • Build up of food between teeth: When teeth are crowded or do not fit together properly, they can trap food and plaque.

  • Old and worn dentures: Ill-fitting dentures can cause bacteria to overgrow and cause bad odor. They can also damage the surrounding tissue and cause a yeast infection known as oral thrush.

  • Smoking: Tobacco and its by-products can leave chemical compounds in your mouth that can cause bad breath.

How to treat and prevent bad breath?

Before you think about treating bad breath, you first need to find the cause, as bad breath is not a disease but a sign of an underlying problem. Therefore, treating the cause means getting rid of bad breath for good.

Since our mouths and oral flora are different, it is not a bad idea to try several solutions to see what works best for you. These include:

1. Temporary relieving bad breath:

This involves using some products to mask temporary bad breath. They are not designed to treat bad breath permanently. However, they can give you temporary relief and can be a good solution, especially if you have a meeting or any kind of social interaction.

Chewing gums:

Chewing gums can reduce temporary halitosis by increasing saliva production. One study has shown that it can significantly reduce the amount of bad breath in your mouth after a few minutes (from 71% to 52%).


Some mouthwashes contain odor-masking agents that can freshen your breath. Those containing chlorine dioxide and zinc salts are known to be very effective in offsetting the bad smell. The zinc can bind to the VSCs and prevent them from volatilizing.

Natural approaches:

Many natural remedies have been proven to temporarily relieve bad breath. The best known are green tea and essential oils.
Green tea has antimicrobial and deodorant properties that can immediately reduce the VSCs in your mouth. Peppermint essential oils can also be effective. They contain menthol, which is known for its pungent and refreshing odor. In fact, most toothpaste and mouthwashes are mint flavored.
Most importantly, drink plenty of water throughout the day. This will prevent bad odor bacteria from overgrowing.


Available everywhere, these are also a good solution for a quick breath fix.

2. Permanent treatment:

The permanent treatment focus on the root cause of halitosis. They consist of improving oral hygiene practices and treating underlying oral conditions (infections, cavities, and gum disease). The goal is to reduce the bacterial charge in your mouth and restore the balance of your oral microbiome for long-term results.

Professional treatment:

Depending on your needs and oral health condition, the treatment at your dentist’s office can be regular or deep dental cleaning, removing the existing cavities or infections, and correcting an ill-fitting filling or restoration. Next, your dentist may prescribe an antiseptic mouthwash to reduce the bacterial load.

If you think your mouth is permanently dry, talk to your dentist. He can suggest solutions, such as artificial saliva, to keep your mouth lubricated and prevent bacteria from building up. These measures will help improve the health of your teeth and gums and cut down on odor-causing bacteria.

Oral hygiene at home:

Good oral hygiene is essential for long-term and permanent results. Using the correct brushing technique and flossing every day is very important. Sometimes, even if your gums and teeth are healthy, bad breath can persist. This is why you should also include tongue cleaning in your oral hygiene routine, as it can be a hiding place for bacteria.

One study showed the role of tongue cleaning in reducing VSC in the mouth. Toothbrushes reduce VSC by 33%, tongue scrapers by 40%, and tongue cleaners by 42%.
In summary, halitosis, commonly known as bad breath, is a common problem caused by various factors, with the mouth being responsible for 90% of cases.
Improving oral hygiene, such as using a tongue cleaner, can help address the issue. If the problem persists, it is recommended to consult a medical professional to rule out any underlying health issues.

  1. Volatile Sulfur Compounds as The Cause of Bad Breath: A Review
  2. Dorsal Lingual Surface and Halitosis: a Morphological Point of View
  3. Effect of chewing gums on the production of volatile sulfur compounds (VSC) in vivo
  4. Effect of green tea on volatile sulfur compounds in mouth air
  5. Effect of essential oils on oral halitosis treatment: a review
  6. Halitosis: From diagnosis to management