Why and how does Canker Sore occurs?

FALSE:: MISTAKE: UNSUPPORTED ENCODING

Canker Sore in throat!!

Canker sore in my throat. The canker sore made it seem like an aching throat, this canker sore was the most awful one i ever had. I am susceptible to canker sores. I use to have like 4 canker sores at once. My mouth is kinda gross cause it harmed way too much to truly brush.