Hi. Welcome to Healthcaremagic. I read your query. Oral ulceration in mouth can be due to several reasons, most common being Apthous ulceration (cause unknown). Other reasons can ce trauma, allergy, medications, radiation exposure, underlying disease etc. If you have history of one of those, I suggest you to consult your physician for treatment of underlying cause. In case of apthous ulcers, the cause is not known. They can be single or multiple ulcers ranging from pun point to larger ones. The small ones heal in 7-10 days while larger one may take upto 40 days to heal. Apthous ulcer may reoccur in 1-4 months or longer. Treatment for these are symptomatic unless underlying cause is known. Avoid stress and anxiety. Take proper rest and sleep. Take multivitamin and mineral tablet one per day. Maintain good oral hygiene with brushing twice a day and use mouthwash. Take healthy diet. Use Lidocaine gel for ease of pain. Apply it before eating also as it will reduce burning. Avoid spicy and acidic food and beverages. If ulcers enlarge or change shape, contact your physician for further tests. Hope the answer helps you. Thank you.