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What will happen to you depends on the type of canker sores you've been getting.

Among people who have recurrent canker sores:¹

• 8 in 10 have minor sores
• 1 in 10 have major sores
• 1 in 10 have herpetiform sores.

To read more about the types of sores, see What are recurrent canker sores?

If you get minor recurrent canker sores, you may get them every one to four months. They should heal within four to 14 days. They shouldn't leave any scarring when they heal.²

We don't know if you will continue to get them, or if you'll stop getting them eventually. But canker sores are more common in teenagers and young adults.³ So you may find you get them less often as you get older.

If you get major recurrent canker sores, you may get them every month. These sores can take more than a month to heal, and may leave scars on the inside of your mouth.²

They tend to start around puberty. One you've started getting them, you may keep getting bouts of them for 20 years or more.⁴

Herpetiform sores can happen once a month and stay for up to a month. But they do not usually leave scars.²

If you have bad sores, your doctor or dentist should check after a few days to see if they are starting to heal. If you have a sore that doesn't heal in two to three weeks, you'll need to see a specialist.⁵

Having recurrent sores can be distressing, especially if they are major sores and cause you a lot of pain. You can take painkillers, like ibuprofen and acetaminophen, to help with the pain.³

If the pain is so bad that you can't eat at all during an attack, you should talk with your doctor about the different treatments available. To read about treatments, see What treatments work for recurrent canker sores? You may need to try a few treatments before you find one that works for you.⁵

If your child has recurrent sores, you'll need to be especially careful that they are eating and drinking enough. If your child refuses to eat at all during attacks, your doctor may be able to suggest ways of ensuring your child gets enough nutrients.⁵

There are some things you can try yourself that may help you avoid getting more canker sores. To learn more, read Self-help to avoid canker sores.

This information is for educational use only, and is not a substitute for prompt professional medical advice. Readers should always consult a physician or other professional for advice and treatment. ©BMJ Publishing Group Limited 2008. All rights reserved.