Polluted Air, Poisoned Breath: How Mouth Breathing In Smoggy Cities Is Triggering Oral Thrush, Bad Breath

Each year, as winter pollution intensifies across Delhi NCR, public concern naturally centres on respiratory health. However, an equally important impact is now being observed within the oral cavity. A growing number of patients are reporting dry mouth, persistent bad breath, recurrent oral thrush, and an overall increase in breathing-related discomfort. A common factor linking these presentations is a progressive shift towards mouth breathing during periods of high pollution.

Lt Gen Dr Vimal Arora (Retd) PVSM, AVSM, VSM & Bar shares all you need to know:

Poor air quality irritates the nasal passages and reduces the ease of nasal airflow. As a result, many individuals begin breathing through the mouth without realising the change. Unlike the nose,

the mouth does not filter, warm, or humidify inhaled air. When it becomes the primary route of breathing, the oral environment undergoes rapid changes. Saliva production decreases, the protective layer over soft tissues thins, and the natural antimicrobial and buffering actions of saliva diminish. In this state, Candida organisms, which are usually well controlled, may multiply, while bacteria associated with bad breath find a favourable environment to grow.

Pollution-related particulate matter further aggravates oral surfaces, settling on the tongue and oral mucosa and contributing to irritation and microbial imbalance. The impact then extends beyond the mouth. When unfiltered polluted air enters the lower airways directly, it can precipitate episodes of bronchospasm, especially in individuals with asthma, allergic airway disease, or chronic obstructive pulmonary disease. During such episodes, the increased effort to draw in air encourages even greater dependence on mouth breathing.

This creates a continuous cycle in which pollution increases mouth breathing, mouth breathing irritates the airway, and airway irritation further increases the tendency to breathe through the mouth.

Certain health conditions intensify this pattern. Allergic rhinitis and sinus infections obstruct nasal breathing and push individuals towards prolonged mouth breathing. Diabetes, immunosuppression, and chronic inflammatory disorders weaken oral tissues and allow fungal infections to progress more easily. Sleep-related breathing disorders also lead to extended periods of mouth breathing at night, which becomes more problematic in polluted environments.

Fortunately, several preventive steps can significantly limit these effects. Regular saline nasal rinses support nasal airflow, adequate hydration helps maintain saliva, sugar-free gum stimulates natural moisture, and routine tongue cleaning reduces bacterial load. On days with poor air quality, using a well-fitted N95 mask can reduce the inhalation of particulate matter. Any early signs of white patches, persistent dryness, or unusual breath should prompt timely dental evaluation.

While the region continues to face environmental challenges, awareness remains a powerful tool. Protecting the oral cavity is essential not only for oral health but also for overall respiratory wellbeing. During periods of persistent pollution, attention to how we breathe becomes an important part of maintaining health.