Hello, You may be suffering from apthous ulcers. Which may be due to unknown cause or bechets syndrome. Until examination is done it is difficult to say what it is. Avoid caffeinated drinks, sleep well, use capsule becosules once a day for ten days. Use salt water gargling thrice a day for five days. Use vitamin c tablet once a day for five days. If no improvement please consult with your physician he will examine and treat you accordingly. Hope I have answered your query. Let me know if I can assist you further. Take care Regards, Dr. Penchila Prasad Kandikattu