Sores in my mouth
Mouth sores can result from trauma, aphthous ulcers, infection, medicines, or systemic illness, and persistent lesions need examination.
The short answer
Mouth sores can result from trauma, aphthous ulcers, infection, medicines, or systemic illness, and persistent lesions need examination. Their location, appearance, duration, and associated symptoms help identify the likely cause.
How can a mouth sore’s appearance suggest its cause?
Aphthous ulcers are often shallow, painful lesions on movable mucosa, while trauma tends to match a mechanical irritant. Herpes viruses commonly affect particular sites, and Candida can cause wipeable or persistent changes in the mucosa. Nutritional deficiency, immune conditions, medicines, and systemic illness can also be relevant.
What can you do for a sore in your mouth now?
Avoid the suspected irritant, choose soft foods, drink fluids, and use a soft toothbrush. Do not pick the lesion or apply caustic chemicals. A pharmacist or dentist can advise on a suitable protective or pain-relieving product after considering your health history. If a sharp tooth, denture, brace, or filling is rubbing the area, arrange correction rather than repeatedly covering the injury.
When does a mouth sore need prompt assessment?
Seek prompt assessment for a sore lasting longer than expected, recurring frequently, becoming larger, or accompanied by fever, weight loss, neck swelling, difficulty swallowing, or reduced immunity. A persistent red, white, firm, or bleeding patch needs examination. Breathing difficulty, severe facial swelling, or inability to drink requires urgent medical care.
What should you ask about a sore in your mouth?
Ask what the lesion looks like, what may have caused it, and whether an examination or swab is needed. Ask how to protect the area while it heals and which medicines fit your medical history. Ask what duration or change should trigger a review and whether an irritant such as a tooth or appliance needs correction.
Frequently asked questions
Are all mouth ulcers caused by stress?
No. Trauma, infection, medicines, nutritional problems, and systemic conditions can also cause sores.
Can I put disinfectant on a mouth sore?
No. Household disinfectants and caustic chemicals can injure oral tissue; use products intended for the mouth.
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Who wrote this page
This library is published by Dental Nation, a licensed dental group practising in the United Arab Emirates. Pages are written and overseen by the same clinical team that treats patients in our clinics, and are held to a fixed editorial standard for safety and accuracy.
This page is patient education, not medical advice, and cannot replace an examination. Anything urgent — facial swelling, trauma, uncontrolled bleeding or severe pain — needs a dentist or emergency care now.