I hate ulcer.

What is the ultimate cause for mouth ulcer?

I heard it can be genetic, or can be caused by virus. Anyway, I got involved. Since I was a child, I often had ulcers in my mouth. It seems ulcers can be propagated. My mom often asked me "Dahong, you have some ulcers in your mouth recently, don't you?" In most case I will answer yes, that means, ulcers can be spread from one person to another through eating in the same plate or share cups with others. So, I would vote for the virus theory. But definitely I am more subject to ulcers than others, that is when my mouth undergoes some injuries, ulcers come to me.

Three days ago I accidentally poked my teeth bed when I was brushing teeth. The result was, I got a huge ulcer until now, when I am writing about this bad guy, it makes me extremely painful. It makes me into the hell even I drink some water and I dare not speak at the early morning - when I got up, the ulcer is stuck to my mouth skin, which gives me a lot of hurt if I try to speak.