Hi Dear , Welcome to HCM. Understanding your concern. Thanks for your query . The symptoms you mention in query are pointing towards a condition known aphthous ulcer. There can be many reason for aphthous ulcer like stress and anxiety ,minor injury inside mouth ,food allergy and vitamin deficiency . They can be rarely associated with disease like corhn s disease . Minor form of ulcers do not required ant treatment ,they go away by there own . I would suggest you to do chlorhexidine mouthwash rinses , apply lidocain gel for pain , do warm salt water rinses several times day ,avoid hot and spicy food and start taking vitamin B12 supplement I condition doesn t get better in 2-3 days consult dentist/oral pathologist for proper examination and to rule out any underlying cause. Hope your concern has been resolved. Please write a review about your experience with me and do click at i find this answer helpful if its valuable for you. Get Well Soon. Best Wishes, Dr. Harry Maheshwari