If you have a mild mouth ulcer, there is no need for you to have a formal diagnosis from your GP. You will also not require any specific treatment, but there are some self-care tips that you can follow to help the ulcer heal faster. See Mouth ulcer - treatment for more information and advice.
Visit your GP if you have a mouth ulcer that is causing significant pain, or if you are getting mouth ulcers on a recurrent basis. Also visit your GP if your mouth ulcer has lasted for more than three weeks.
Your GP may look inside your mouth to examine your mouth ulcer. They will also look at your medical history to help them work out what is causing your ulcer.
Recurring ulcers
If you have recurrent mouth ulcers (ulcers that keep coming back), your GP may ask you a series of questions to help determine whether your mouth ulcers have an underlying cause. For example, they may ask you about:
- the frequency of your ulcers (how often they occur)
- how long your ulcers last for
- how severe the pain is
- what treatments you have used - either prescribed or over the counter
If your GP is unsure about the diagnosis, they might want to rule out any conditions that could be causing your ulcers to keep recurring. They may refer you for a series of blood tests. The tests that you have may include those outlined below.
- Full blood count (FBC). This is a common type of blood test that indicates the state of your general health. It will show whether there is an infection in your body, and will also indicate whether you have been exposed to any toxic substances.
- Erythrocyte sedimentation rate (ESR). This test will not confirm a specific condition but it will show whether there is inflammation in your body. If there is inflammation, your GP can conduct further tests to help determine what condition may be causing it.
- Ferritin. This test measures how much iron is being stored in your body. A lack of iron in your body can cause recurrent mouth ulcers.
- Vitamin B12. This test checks whether you have enough vitamin B12 in your body. A lack of vitamin B12 can also cause recurrent mouth ulcers.
Referral
If you have had a severe mouth ulcer for more than three weeks, your GP may to refer you to a specialist. You may require a biopsy (a procedure in which a small tissue sample is taken for further examination) to help determine the cause of your ulcer.
You will also be referred to a specialist if your mouth ulcers are abnormal in appearance. For example, some people develop large red and white patches in their mouth, which often bleed and are painful. If this is the case, you may be referred for further examination.
Mouth cancer
It is very important to visit your GP if your ulcer has lasted for more than three weeks or it appears abnormal. For example, if it is made up of large red and white patches that often bleed.
This is because a severe, long-lasting mouth ulcer can be a sign of mouth cancer. For example, about 80% of people with mouth cancer have a long-lasting mouth ulcer that does not heal.
Ulcers caused by mouth cancer usually appear on or under the tongue, although they can appear elsewhere in the mouth.
You are more at risk of developing mouth cancer if you are:
- male
- over 45 years old
- a heavy smoker
- a heavy alcohol drinker
If mouth cancer is detected at an early stage, the chances of a complete recovery are good. This is why it is always important to have regular check-ups with your dentist. They can carry out a thorough assessment of your teeth and mouth, and will be able to spot any possible signs of mouth cancer.
See the Health A-Z topic about Mouth cancer - introduction for more information and advice.
