Canker sores are typically triggered by too much sugar or fructose consumption (fruit too!) even in an otherwise healthy diet.
You can get mouth ulcers that keep coming back, mainly at times when you’re particularly stressed, anxious or ‘run down’. Some women can also develop them during hormonal changes such as pregnancy or their monthly period.
Best prevention is
-avoiding certain foods – such as chocolate, spicy foods, coffee, peanuts, almonds, strawberries, cheese, tomatoes and wheat flour, if they cause you to have an ulcer.
-not chewing gum.
-brushing your teeth with a soft-bristled brush, which may reduce irritation in your mouth.

Hope your mouth ulcers have stopped occurring !

My mum found that taking a zinc supplement reduced her mouth ulcers.

A mouth ulcer is the loss or erosion of the delicate lining tissue of the mouth (mucus membrane).
The most common cause is mechanical injury, such as accidentally biting your cheek.
In most cases, mouth ulcers are harmless and resolve by themselves in a few days without the need for medical treatment.
If your mouth ulcers don’t clear up within a few days, or if you are troubled by frequent attacks, see your doctor.

My partner and our eldest son both get them. My youngest and I don’t. Recently I’ve made an effort to cut down the sugar in our kids diet and just thinking about it now he hasn’t had an ulcer for awhile.

It can be from foods or even medicines. I can get them from chocolate, coffee and other dairy products while my hubbies triggers are chocolate and using his ventolin. Be mindful to rinse your mouth often, especially after medications. Kenalog is very soothing and helps to get rid of them.

A trip to your GP would be wise. Perhaps you are just lacking a vitamin but best to check it out.

A chemist will also be able to give you something to relieve the pain and discomfort of the ulcers.

Mouth ulcers may be caused for many reasons. A GP will be able to diagnose and treat ulcers.

you sound run down. you can use mouth ulcer gel. Maybe avoid really hot foods. What is your diet like?

I am currently under the care of a rheumatologist and going through testing. I had a hip replacement at 23 now 27 after having 2 kids seem to be having a flare, I didn’t realise the mouth ulcers may be connected to the connective tissue issue they think j have!

Can be something minor like a a deficiency (in zinc, B12, folate, iron) or reaction against citrus or hormone related (is there a pattern?). Or a symptom of something more serious to do with inflammatory response of body, IBS, and other chronic diseases. I’d check with doctor if you were concerned, they were persistent, painful or just occurring a lot.