When to see your GP

  1. If you have a mild mouth ulcer, there is no need to visit your GP
  2. Do visit your GP if you develop an ulcer somewhere else on your body, such as your genitals, or if you have a mouth ulcer that:
    • gets more and more painful and inflamed
    • lasts for more than three weeks. [19]

Potential other causes of mouth ulcers [19]

  1. If you have mouth ulcers that keep coming back, your GP may want to work out whether something else is causing them. 
  2. This might include having some blood tests to look at your general health, to test whether there is inflammation in your body, or to check whether you have enough iron and/or vitamin B12 in your body. A lack of iron or vitamin B12 can cause mouth ulcers.
  3. If your mouth ulcer doesn’t look like a normal mouth ulcer (for example if you have large red and white patches in your mouth which often bleed and are painful), or you have had a severe mouth ulcer for more than 3 weeks, your GP could refer you to a hospital specialist. The specialist may then take a small sample of tissue from inside your mouth for further examination.
  4. Sometimes, a severe, long-lasting mouth ulcer can be a sign of mouth cancer. About 80% of people with mouth cancer have this type of mouth ulcer.
  5. Mouth ulcers caused by mouth cancer usually appear on or under the tongue, although they can appear elsewhere in the mouth.
  6. You are more at risk of developing mouth cancer if you are:
    • male
    • over 45 years old
    • a heavy somker
    • a heavy alcohol drinker
  7. If mouth cancer is spotted early, the chances of a complete recovery are good. This is why it is always important to have regular check-ups with your dentist.