Question: why does the roof of my mouth hurt when my tongue touches it?
Answer: Before they become obvious spots or blisters, cold sores and canker sores may cause swelling on the roof of your mouth. Stress and hormonal changes may trigger a canker sore. Many canker sores develop on your cheek or the gums near your teeth, but it's not uncommon for them to appear on the roof of your mouth, too.