Mr. lybrate-user, Mouth Ulcers can happen due to a lot of problems. Most common is any kind of stress
. But there are multiple reasons due to which ulcers can become chronic and cause more harm. Stress related ulcers will usually go away once the reason for stress is gone. Taking good diet
rich with vitamin B generally helps. But ideally you should show it to your nearby dentist
and get it thoroughly checked.