What Causes Canker Sores?

What Causes Canker Sores

What Causes Canker Sores?

Canker sores are small, round ulcers found inside the mouth. Unfortunately, canker sores are pretty painful and can make eating uncomfortable. You can avoid this nasty oral wound by learning what causes canker sores and the steps you can take to prevent them.

Types of Canker Sores

Canker sores are usually found on the inside of your mouth and on the lining of your lips, gums, and cheeks. You may also get a canker sore on/underneath your tongue. Canker sores are typically white, gray, or red, though the color may vary.

There are three different types of canker sores:

  • Minor Canker Sores: The most common type of canker sore. Minor canker sores usually last between 10 to 14 days and heal without scarring.
  • Major Canker Sores: Less common and much larger than a Minor canker sore. Major canker sores can take weeks to heal and may leave heavy scarring.
  • Herpetiform Canker Sores: Rarest type of canker sore. Herpetiform canker sores are very small (2-3 mm) and appear in clusters of 10-100 sores. They usually take a week to heal. 

What Causes Canker Sores?

If you’re wondering why you’re battling a canker sore, or you simply want to avoid the chances of them altogether, here are the factors that may potentially cause canker sores:

  • Hormonal changes
  • Recent dental work/sports injury
  • Food/diet sensitivities, especially acidic food
  • Brushing your gums too hard
  • Stress
  • Lacking B12, zinc, folic acid, and iron
  • Celiac disease and/or inflammatory bowel diseases (Crohn’s disease)
  • Other underlying health conditions

20% of people suffer from canker sores regularly, with women being more susceptible to these oral ulcers than men.


Unfortunately, canker sores can make everyday life necessities like eating uncomfortable. You’ll probably want to seek relief from the burning and pain as soon as possible. If you’re suffering from a canker sore, try out these treatments: 

  • Over the counter products such as Orajel or Kank-A
  • Antibacterial mouth rinse
  • Saltwater rinse
  • Switch to a soft-bristle toothbrush to avoid irritation
  • Soothe irritation by rubbing aloe vera on the canker sore

If the pain seems to worsen over time, contact your doctor. They may prescribe you a steroid rinse or pill to clear out the ulcer. 

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