Gastroesophageal Reflux Disease (GERD) and its variant, Laryngopharyngeal Reflux (LPR), are conditions where stomach contents move backward into the esophagus and sometimes into the throat and mouth. Canker sores (aphthous ulcers) are common, painful lesions appearing on the soft tissues inside the mouth. People with frequent acid reflux often wonder if the highly acidic contents cause these sores. While reflux is not the direct trigger for typical canker sores, chronic exposure to stomach acid can severely irritate the oral lining, leading to lesions that mimic or exacerbate existing ulcers.
What Standard Canker Sores Are
A standard canker sore (aphthous ulcer) is a distinct, non-contagious lesion that forms on the oral mucosa. These sores are typically round or oval and feature a white, grey, or yellowish center surrounded by a bright red border or halo. They most often appear on non-keratinized tissues like the inside of the cheeks, the lips, the floor of the mouth, or the tongue’s underside. A minor aphthous ulcer is usually small, less than five millimeters in diameter, and tends to heal naturally within seven to fourteen days without scarring.
The exact cause of these ulcers is not fully understood, but they are often linked to a disturbed immune response. Minor trauma, such as accidentally biting the cheek or irritation from dental work, is a frequent local trigger. Systemic factors also contribute, including emotional stress, hormonal shifts, and nutritional deficiencies in elements like Vitamin B12, folate, or iron. These are considered primary aphthous ulcers and develop independently of stomach acid exposure.
How Reflux Affects Oral Health
Acid reflux, particularly LPR, is the mechanism through which stomach contents can reach the oral cavity. Unlike classical GERD, which presents with heartburn, LPR often involves the reflux of acidic vapor and the enzyme pepsin, reaching the throat and mouth without noticeable chest symptoms, earning it the nickname “silent reflux.” The stomach acid involved has an extremely low pH, which is highly damaging to tissues not designed to withstand it.
The sensitive oral mucosa and throat are exposed to this harsh acidic environment, which can lead to generalized inflammation and mucosal damage. Chronic acid exposure can cause palatal erythema, a persistent burning sensation in the mouth, and an increased likelihood of developing non-specific mouth sores. Research indicates that this chronic irritation can weaken the mucosal barrier, potentially making the mouth more susceptible to ulcer formation or slowing the healing of pre-existing ulcers. Some studies link GERD to mouth ulcers, though these lesions often present as erosions or “aphthoid lesions” rather than classic aphthous ulcers. The primary damage from acid exposure is often observed as dental erosion on the back teeth, but soft tissue irritation is a related manifestation of the same corrosive process.
Targeted Relief and Medical Guidance
When oral lesions appear alongside symptoms like a persistent sore throat, chronic cough, or a sensation of a lump in the throat, it is prudent to consider reflux as a contributing factor. Management involves strategies focused on reducing the frequency and impact of acid reaching the mouth. Simple lifestyle adjustments can significantly reduce oral acid exposure, such as waiting at least three hours after eating before lying down or going to sleep.
Dietary modifications are also helpful, including reducing highly acidic foods and beverages that can lower the oral pH. Elevating the head of the bed by six to eight inches can use gravity to prevent nighttime reflux episodes. Using alkaline water to rinse or sip after a potential reflux event can help neutralize the acid. If mouth sores are recurrent, severe, or accompanied by classic reflux symptoms like heartburn, consultation with a healthcare provider (gastroenterologist or otolaryngologist) is necessary. Diagnosis may involve procedures like pH monitoring or endoscopy to confirm the severity of the underlying reflux condition.