Why Chronic Halitosis Is So Hard to Diagnose: A Clinical Gap in Care

The Diagnostic Puzzle

People with long‑term halitosis often see several providers: dentists, ENTs, gastroenterologists, and others before they reach a specialized breath clinic or get a clear explanation. Many are told that exams and standard tests are normal, even after multiple visits, which adds to their frustration and delay in appropriate care.
(International Journal of Oral Science, 2012)

This experience is more common than most people realize, and studies show that people with halitosis often face embarrassment, anxiety, and social limitations, especially when no clear cause is found. The problem is deeper than just needing a better cleaning routine: chronic halitosis is often multifactorial, driven by oral biofilm, saliva flow, local inflammation, sinus or airway disease, and shifts in the oral microbiome. Yet despite this complexity, there is still no widely adopted, standardized diagnostic pathway to untangle these overlapping causes across different specialties.

Why the System Fails

Clinicians are typically trained to look first for obvious causes like poor oral hygiene, gum disease, or sinus infection, and most dentists and physicians focus on these common sources when someone complains of bad breath. But complex cases, especially those driven by extra‑oral or systemic factors, are at higher risk of being overlooked or managed in isolation by different providers, because there is often no structured, interdisciplinary referral pathway for halitosis. In fragmented systems, a person with sinus‑related halitosis may spend multiple visits in dental care before being sent to ENT, and potential contributors like oral microbiome imbalance are rarely examined in a systematic way at all.
(Cureus, 2023)

What makes this worse is that despite available diagnostic tools organoleptic scoring, gas chromatography, and sulfide monitors - there is still no widely adopted, standardized diagnostic pathway for chronic halitosis across specialties. A study of volatile sulfur compound measurement using the cysteine challenge test noted that key parameters remain undefined and that a standardized protocol has yet to be established for this diagnostic approach. Reviews also highlight major methodological inconsistencies across halitosis research and the lack of sufficient evidence to guide clinicians in choosing among different tests. In practice, this means many clinicians are still synthesizing fragmented data rather than following a clear, evidence‑based guideline for diagnosis.

What Needs to Change

Current literature highlights the need for standardized diagnostic protocols, more microbiome‑driven research, and multidisciplinary halitosis clinics. Studies of dedicated halitosis clinics show that structured, team‑based assessment can reduce time to diagnosis, patient frustration, and unnecessary investigations compared with the usual scattered approach. The evidence base is there, but it is spread across dental, medical, and research journals, and surveys suggest that many general practitioners receive limited halitosis training and feel under‑prepared to manage these cases confidently.
(Frontiers in Oral Health, 2023)

The Bottom Line

Chronic halitosis is not just a lifestyle problem; it is often linked to underlying oral or systemic conditions that require proper diagnosis. Rather than being a sign of poor hygiene or social neglect, it's frequently a diagnostic blind spot that sits between specialties. The frustration patients feel is real and so is the gap between their needs and the current evidence base.

The good news: awareness of this gap is growing. Interdisciplinary research is expanding, microbiome-focused studies are multiplying, and clinical leaders are building models for better halitosis care. Patients deserve a pathway that doesn't require years of appointments to get answers.

Feno products are consumer oral care devices and are not medical devices. They are not intended to diagnose, treat, cure, or prevent any disease.