The main cause of bad breath is the release of volatile sulfur compounds in the oral cavity. Below are the reasons why this compound evaporates.

1.1 Bad breath caused by bacteria

Volatile sulfur compounds are caused by Gram-negative anaerobic proteolytic bacteria. These bacteria are often located in stagnant areas of the mouth, such as periodontal pockets, the tongue surface or the interdental area between teeth and in carious lesions.

1.2 Causes of temporary bad breath

• When eating foods that contain substances that dry the mouth, such as alcohol, cigarettes, or foods that provide high protein and sugar content such as milk, when decomposed in the mouth, they will release amino acids containing very many sulfur compounds;
• Onions and garlic are also foods that contain high levels of sulfur, which can pass through the intestinal lining into the blood, then release into the lungs and evaporate out;
• Smoking not only increases the content of volatile substances in the mouth and lungs, but also aggravates bad breath, because it affects and dries the oral mucosa;
• Bad breath in the morning after waking up is also associated with reduced saliva production and secretion, leading to temporary dry mouth and bad breath.

1.3 The cause of bad breath comes from the mouth

• Periodontal and gum diseases such as gingivitis, periodontitis, or acute necrotizing ulcerative gingivitis, pericoronitis, peri-implantitis, abscesses causing bad breath;
• Ulcers due to malignancy, local causes, aphthous or the effects of some drugs are also causes of bad breath;
• Reduced salivation with age, medication use, radiation therapy, chemotherapy, and Sjogren's syndrome causes bad breath;
• Poor oral hygiene, tongue residue, or Candida fungal infection also cause bad breath;
• Deposition of debris on orthodontic devices such as dentures, appliances, etc. is one of the causes of bad breath;
• Bone diseases such as osteomyelitis, osteonecrosis, or dry socket and other malignancies can also cause bad breath.

1.4 Other causes of bad breath

Frequent bad breath can be due to causes outside the mouth such as:

• Use of certain drugs: Drugs that can cause bad breath such as amphetamine, chloral hydrate, cytotoxic drugs, dimethyl sulphoxide, disulfiram, nitrate and nitrite, phenothiazine;
• Systemic diseases: Nasopharyngeal infections such as respiratory disorders (nose, sinuses, tonsils, pharynx), can lead to bad breath;
• Gastrointestinal diseases: Bad breath is considered a typical and frequent symptom of gastroesophageal reflux disease. Helicobacter pylori infection also causes stomach ulcers, which is also a cause of bad breath;
• Diabetes, liver and kidney diseases, etc. can also lead to the risk of bad breath due to the breakdown of fat in the body;
• Rotten fish odor syndrome: This is a very rare genetic syndrome. The cause is that the body has a metabolic disorder, not metabolizing trimethylamine found in fishy-smelling foods, causing the chemical to accumulate inside the body, especially in the liver, before the substance is excreted. go out.

When discovering persistent bad breath, the patient needs to see a doctor to determine the cause. Most common causes are poor oral hygiene and dental diseases. Therefore, first, the patient needs to go to the dental clinic to determine the cause in the mouth. If there is an infection in the mouth such as tartar, cavities, plaque, periodontitis, the patient needs treatment. dental interventions first.

If bad breath is not due to causes in the mouth or after dental intervention, the patient still has bad breath, then the patient needs to see other specialists such as ear - nose - throat, gastroenterology, urology... to check. have appropriate treatment intervention.

Some temporary ways to cure bad breath include using gum or mouthwash, mouth spray after smoking, and eating onions and garlic.

Consider using some medications that reduce saliva secretion causing bad breath. In addition, patients should also pay attention to drinking water regularly to avoid dry mouth.

To reduce and prevent bad breath, you need to pay attention to oral hygiene. You need to practice oral hygiene properly, brush your teeth twice a day, in the morning after waking up and at night before going to bed. Use dental floss, tongue scrapers and mouthwash to limit plaque formation. Have regular dental check-ups every 4-6 months and perform dental interventions when needed. After eating, you should rinse your mouth with a small sip of water to wash away any remaining food. Shaving your tongue daily helps remove bacterial plaque on the tongue's surface.