Ulcer in your mouth can make eating and talking uncomfortable. They’re also known as aphthous ulcers.
There are a few types of canker sores:
- Minor canker sores. These may show up three or four times a year. They typically happen in people ages 10 to 20. They’re less than 1 centimeter across and heal in about a week with no scarring.
- Major canker sores. These are less common. The ulcers are bigger and can last more than 2 weeks. They often heal with scarring.
- Herpetiform canker sores. These are rare and show up as clusters of tiny ulcers. They usually heal in about a week.
Canker Sore Causes and Risk Factors
Doctors don’t know what exactly causes most canker sores. Things that might cause minor sores include:
- Stress
- Tissue injury, like from a sharp tooth or a dental appliance
- Certain foods, including citrus or acidic fruits and vegetables (such as lemons, oranges, pineapples, apples, figs, tomatoes, and strawberries)
- Nonsteroidal anti-inflammatory drugs like ibuprofen
- An allergy to something in your food or in your toothpaste or mouthwash
- Helicobacter pylori, the bacteria that can cause peptic ulcers
Things that might cause complex canker sores include:
- An underlying health condition like a weakened immune system, HIV/AIDS, lupus, or Behcet’s disease
- Nutritional problems like too little vitamin B12, zinc, folic acid, or iron
- Gastrointestinal diseases like celiac or Crohn’s
About 1 in 5 people gets canker sores regularly. They’re more common in women, possibly because of hormonal differences. They may also run in families.