Many people suffer from persistent bad breath, even after trying various remedies. In reality, unpleasant breath is not always a result of poor oral hygiene; it can also be a symptom of deeper systemic issues such as ENT disorders, digestive problems, hormonal imbalances, lung conditions, or even nutritional deficiencies.

A comprehensive, multidisciplinary approach to diagnosis and treatment is essential for identifying the root cause of persistent bad breath and detecting any potentially serious underlying conditions at an early stage.

The Confidence Crisis Triggered by Chronic Bad Breath

Struggling with persistent bad breath despite following regular oral hygiene routines is a frustrating and demoralising experience for many. On an online forum called the “Anti-Halitosis Community,” which has over 10,000 members, countless individuals openly share their struggles with this sensitive issue.

One mother, after giving birth, found herself battling persistent bad breath despite brushing her teeth three times a day. She became increasingly self-conscious and began avoiding social interactions. Another member shared that she could even detect the unpleasant smell herself, saying, “Every time I go somewhere, I feel guilty as if I’m bothering other people.”

People with persistent bad breath often resort to a wide range of remedies: brushing their teeth excessively – sometimes to the point of damaging the enamel, using mouthwash, chewing mints, or experimenting with traditional folk remedies. Yet, the unpleasant odour persists.

Anxiety over bad breath leads many to cover their mouths while speaking, hesitate to contribute during group discussions, or avoid job interviews for fear of making a poor impression. Some miss out on career opportunities or feel uncomfortable interacting with clients and business partners. For others, the worry is so overwhelming that it discourages them from pursuing romantic relationships.

Breath Odour: A Warning Sign of Underlying Health Issues

According to Nguyen Thanh Tung, MD, PhD, Head of Oral & Maxillofacial Surgery – Dental Surgery Department at FV Hospital, the causes of bad breath can be classified using the 80/20 principle. He explains that around 80% of cases originate within the mouth, making it the most common source of causes. These include gingivitis, periodontitis, tongue coating, tooth decay, and dry mouth, among others.

The remaining 20% of halitosis cases originate from causes outside the oral cavity. These systemic factors are often overlooked and require a broader, more comprehensive diagnostic approach.

According to Vo Cong Minh, MD, PhD,  Head of the ENT Department at FV Hospital, infections related to ear, nose, and throat conditions can result in unpleasant breath odour. “Bacteria thrive in mucopurulent secretions, producing foul smells. For instance, in cases of sinusitis, postnasal drip can lead to bad breath. Tonsillitis is also a very common cause—especially when tonsil stones (tonsilloliths) are present. In addition, chronic pharyngitis may also contribute to persistent breath odour.”

Bad breath can also result from digestive conditions such as gastroesophageal reflux disease (GERD), gastritis caused by Helicobacter pylori (H. pylori) infection, and colitis. According to Specialist Level II, Bui Nhuan Quy, MD, MSc, Head of the Gastroenterology and Hepatology Department at FV Hospital, patients who were successfully treated for these gastrointestinal conditions often reported a noticeable elimination of unpleasant breath odour.

Diet can also be an unexpected cause of bad breath. Specialist Level II, Nguyen Viet Quynh Thu, MD, MSc, Head of the Dietetics & Nutrition Department at FV Hospital, explains: “A very popular diet today is the Keto (low carbohydrate) diet. When carbohydrate intake is severely restricted, the body enters a state of ketosis, burning fat instead of carbohydrates to produce energy, which generates ketones, including acetone, a substance that can be released through breath and cause an unpleasant odour, known as ‘ketone breath’.”

A Multidisciplinary Approach to Effectively Resolving Bad Breath

At FV Hospital, persistent bad breath is regarded as a medical issue that requires comprehensive diagnosis and treatment. FV applies a multidisciplinary approach, fostering close collaboration between the Oral and Maxillofacial Surgery – Dental Surgery, ENT Department, Gastroenterology and Hepatology, Dietetics and Nutrition, Endocrinology and Diabetology, and Clinical Psychology Departments, depending on the specific case.

Patients seeking treatment for bad breath at FV Hospital are first referred to the Oral and Maxillofacial Surgery – Dental Surgery Department to examine and address the 80% of causes that originate within the mouth. Dentists will treat any dental conditions and provide detailed instructions on proper oral hygiene and maintenance to help patients achieve optimal oral health and prevent bad breath caused by the oral factors.

If no issues are identified in the oral cavity, patients will be referred to other relevant specialties for future evaluation. They may be directed to the ENT Department for endoscopy to detect inflammatory sites or nasal structure abnormalities that could lead to fluid retention. Alternatively, they may be referred to the Gastroenterology and Hepatology Department for gastric endoscopy and H. pylori testing. In some cases, patients are assessed by the Endocrinology Department for blood tests to check blood sugar, liver, and kidney function.

If all physical causes are ruled out, FV’s Dietetics & Nutrition team will assess the patient’s eating habits, with particular attention to low-carbohydrate or Keto diets, which can lead to ketone production that cause a strong, pungent breath odour. Based on the assessment, the team will then develop a personalised plan to adjust the patient’s diet, ensure balanced nutrition, and, if necessary, incorporate structured weight loss.

The psychological impact of bad breath should not be overlooked. In some cases, it can lead to “pseudo-halitosis” or “halitophobia” where individuals become excessively anxious about having bad breath, even when no odour is present. This persistent fear can cause significant anxiety, low self-esteem, and social withdrawal, requiring support from mental health professionals. At FV Hospital, psychological care is an essential part of patient management. In suspected cases of pseudo-halitosis or halitophobia, a clinical psychologist will be involved to provide appropriate support.

Persistent bad breath is a complex medical issue. Rather than feeling embarrassed or relying on temporary fixes, individuals are encouraged to view bad breath as a potential health warning that deserves in-depth consultation and treatment to address the root cause. To schedule a consultation for persistent bad breath, please contact the Oral & Maxillofacial Surgery – Dental Surgery Department at FV Hospital at: 028 3511 3333.