physical education. n. (Education) training and practice in sports, gymnastics, etc, as in schools and colleges. Abbreviation: PE. physâ²ical educaâ²tion. n. instruction in sports, exercise, and hygiene, esp. as part of a school or college program.
3. Stress/injury. Stress on the tissues or any type of injury in the mouth can cause canker sores. Since the sores are actually tiny ulcers, they can be caused by any kind of hard brushing or eating something that can cause bruises or lead to tissue inflammation in the mouth.
Canker sore is a type of ulcers that causes the formation of blood blister in mouth. They are formed after the invasion on microorganisms in the mouth. They may occur on the various parts of the mouth such as under the tongue, inside cheeks and on gums. There are various drug that causes blood blisters.