Canker pain packs a punch but can be prevented.

Byline: Cheryl Powell

Anybody who's ever had a canker sore has undoubtedly wondered: How can such a little thing cause so much pain?

Despite all the modern-day medical advances, the causes and cure for the common canker sore continue to be elusive.

"The story about canker sores is how much we don't know," said Kimberly Harms, a Farmington, Minn., dentist and consumer adviser for the American Dental Association. "We don't know a lot about them. We do know they hurt."

There are some things people can do to try to prevent these typically harmless, albeit annoying, sores and to cope with them once they develop.

For the most part, though, it's not necessary to seek professional help, said Dr. Tanya Edwards, a family practice physician at University Hospitals in Cleveland, Ohio.

"Everybody takes care of this stuff at home," she said.

Canker sores _ technically known as aphthous ulcers _ are noncancerous, open sores in the mouth that appear as a painful white or yellow ulcer surrounded by a bright red area. Some canker-sore…