About 20 percent of Americans are prone to canker sores -- painful mouth ulcers that spring up for a short while and then disappear. Luckily, there are ways to prevent and treat them. Here are just a few:

1. Keep That Mouth Clean. If you develop a canker sore, use an antimicrobial mouthwash (like Listerine) to prevent them from becoming infected and lessen the severity of pain.

2. Put Down the Wasabi. Avoid eating hot, acidic and/or spicy foods, as they may exacerbate pain and work to lengthen the sore's sojourn on your mouth.

3. Lube Up. Apply over-the-counter anti-inflammatory cream to the infected area. If this doesn't help, ask your dentist or doctor, who can prescribe an antibiotic.

4. Chill Out. Because stress can trigger or worsen an outbreak, engage in stress-reducing activities.

5. Boost Your B12. Research shows a potential link between a deficiency in this vitamin with the outbreak of canker sores.

If symptoms don't go away in two weeks, go see your dentist or doctor. Although canker sores are, by themselves, relatively harmless, they may sometimes be a sign of a more serious problem, such as gum disease or even oral cancer.