This page is for non-emergency concerns. If you have severe or rapidly worsening symptoms (trouble breathing, chest pain, signs of stroke, severe allergic reaction, uncontrolled bleeding, fainting, confusion), call 911 or go to the nearest emergency room.
A Mouth Sore Is Not Always the Same Thing
A tender spot on the inside of your cheek, a blister at the lip and irritation caused by a sharp tooth may all be described as a “mouth sore.” They do not necessarily have the same cause or treatment. Their location, appearance, duration and other symptoms help determine what to do next.
Canker sores usually occur inside the mouth and are not contagious. Cold sores, often near the lips, are usually caused by herpes simplex virus and can spread to others. Trauma from biting the cheek, braces or a poorly fitting dental appliance can also produce painful areas. Some persistent sores need evaluation for other medical or dental conditions.
The Details That Help an Evaluation
Before a visit, note where the problem began, whether it has happened before, and how long it has lasted. Is the area an open ulcer, a cluster of blisters or a painful swelling? Does eating acidic food make it worse? Have you started a new medication or used a new oral-care product?
Your clinician may inspect the mouth and discuss symptom relief, possible infection, medication risks, or whether follow-up with a dentist or another specialist is more appropriate. A visit does not replace dental treatment for a damaged tooth or a dental abscess.
Comfort Without Making It Worse
Soft foods, cool drinks and avoiding foods that irritate the sore may be helpful. Maintain gentle oral hygiene. Do not pick at lesions or share lip balm, utensils or drinks when a contagious cold sore is possible. Over-the-counter products may ease discomfort for some patients, but use caution with topical numbing agents and follow age-appropriate directions.
When Mouth Pain Needs Prompt Attention
Seek urgent assessment for a sore that persists, repeats frequently, makes it hard to eat or drink, or comes with fever or increasing swelling. A mouth lesion that does not heal—especially if it lasts around two weeks—should be evaluated. Rapidly progressing facial or throat swelling, trouble breathing, inability to swallow saliva or severe dehydration requires emergency care.
Common Questions
Are canker sores and cold sores interchangeable terms? No. They differ in cause, typical location and whether they are contagious.
Will every mouth sore require an antibiotic? No. Many lesions are not caused by bacterial infections, and treatment depends on the examination.
Related reading: Sore throat evaluation and skin and rash concerns.
Visit: Arrange an Express Clinic visit or call (440) 624-4026. The $75 seasonal exam rate (normally $125) ends March 1, 2027; separate charges may apply.
Medical sources: MedlinePlus — Mouth sores; MedlinePlus — Canker sore.
This page is for non-emergency concerns. If you have severe or rapidly worsening symptoms (trouble breathing, chest pain, signs of stroke, severe allergic reaction, uncontrolled bleeding, fainting, confusion), call 911 or go to the nearest emergency room.