Mouth ulcers such as sores, canker sores, blisters and oral inflammation are very common conditions.

Sores and blisters in the mouth can be particularly disabling, especially during heavy treatments such as cancer chemotherapy. There are chronic forms of these ulcers: aphtosis or stomatitis.

Before describing the causes and best remedies for mouth ulcers, let’s put the context together to answer the following question:

solution to canker sores

What is a mouth ulcer ? What are the causes of these blisters in your mouth?

An ulcer looks like a blister in your mouth. It has a round or oval shape. It’s an ulceration of the mouth, a small wound that can be very painful before it’s completely scarred.

The ulcers develop in the mouth, on the inner surface of the cheek, on the gums and on the tongue.


As a generally known fact, an ulcer takes a week to heal. However, in severe forms and during certain treatments, such as cancer treatments, the blister that forms the mouth ulcer can take much longer to disappear.


Sometimes, superinfection with the herpes virus is possible. In this case, your doctor may prescribe an acyclovir-based medicine.


The main causes of mouth ulcers

The causes of the appearance of a canker sores are not always well established. It seems that stress, injuries in the mouth, fatigue, a special sensitivity to certain foods (nuts, spices …), deficiencies of zinc, iron or vitamin B12, the use of certain toothpastes (with sodium lauryl sulphate for example) may be factors that increase the likelihood of one of these painful blisters appearing in the mouth.


Beside these causes, heavy treatments such as chemotherapy, are causes of the appearance of ulcers mouth. This is one of the most common side effects together with fatigue, hair loss, nausea.

Indeed, the action of chemotherapy will destroy the cancer cells, but also temporarily weaken the immune system of the sick person, hence the appearance of ulcers.


Prevent the appearance of mouth ulcers

To prevent the appearance of canker sores, try to identify foods for which there is sensitivity and avoid them in the preparation of meals.

Alcohol consumption is irritating to your mouth, it is better to reduce it as much as possible.


It’s advised to have a very soft toothbrush to avoid injuring of the gums and oral mucosa. If you have a sore mouth, try using a postoperative toothbrush or a thoothette © (it’s a stick with a foam tip, used as an alternative to the toothbrush)


Chemotherapy and canker sores prevention

In general and before the start of chemotherapy, you have to get a check-up at a dentist. This is important to avoid infections that may come from a sick or unhealthy tooth. All sources of infection can have very serious consequences when administering cancer treatments such as chemotherapy.


In addition, your medical team will prescribe a special « chemo » mouthwash based on bicarbonate. The medicinal bicarbonate is very pure. For the preparation of this mouthwash, its quality must be irreproachable. On the other hand, you should not use the mouthwashes of the supermarket. They contain alcohol and are irritating to the oral mucosa.

These mouthwashes specific to « chemotherapy » should not be kept more than three weeks after opening.

After each toothbrushing, it will be necessary to use a mouthwash that contains bicarbonate. It’s also advised to gurgle.


Some patients use mouthwashes with probiotics to promote the proper balance of the oral flora. Ideally, ask your doctor about this procedure.


To avoid the recurrence of mouth ulcers, it is better to change your toothbrush often and after each appearance of these painful mouth « blisters ». Also, remember to dry your toothbrush to avoid infections as described in the article on aplasia.


Water heavily loaded with bicarbonate can reduce the acidity of the mouth and therefore reduce the risk of mouth ulcers. In France, we have the waters Saint Yorre (4,365 mg/l), Vichy-Celestin (2,989 mg/l), Ardesy (2,195 mg/l), and Rozana, which are marketed in bottles in supermarkets. There may be other sources, in the United States and around the world, with waters that contain a lot of bicarbonate. To find out the amount of water bicarbonate, just look at the bottle label and compare the values with the mineral water I mentioned.

Be careful, in case of heart failure, it seems that drinking these waters is contraindicated.


Finally, if you have chemo sessions that last a short time (maximum a few hours), you can try to suck on crushed ice to prevent the appearance of the blister of the mouth ulcer (if you do not have mouth cancer).


In addition, here is a video that I find interesting about the prevention of mouth ulcers, carried out by the Norton Cancer Institute:




The best remedies for mouth ulcers (canker sores / blisters in the mouth)

Once the canker sores is there, the mouth can become very painful.

Your doctor can accompany you by finding the best remedies to relieve you. You can also ask for a consultation with a doctor-nutritionist or dietician who will support you with personalized indications.


Food, meals and mouth ulcers

In the preparation of meals, avoid eating warm meals. Also avoid spicy dishes or dishes that contain acidic ingredients (dried fruit, pineapple, tomatoes, vinaigrette, fruit juice, mustard, wasabi). Do not eat cooked cheeses or hard foods (crackers, crisps, chips, crust of bread, toasts).


You must also avoid drinking very sweet drinks (soda…even if some patients consider that cola reduces nausea… which is a big problem for the quality of the chemo diet).


Fluid foods can help reduce pain. We must focuse on soups, mashed purées, compotes. The trick to avoid the pieces is to grind the vegetables with cooking water.

To balance the oral flora and prevent the appearance of mouth ulcers, you can also try to eat a yogurt containing probiotics every day. Nature hates emptiness. The more good bacteria in your mouth (good for you), the less room there will be for viruses, harmful bacteria and fungi that want to colonize your mouth. This is the same principle with the intestines that can contain 1 kg of bacteria.


Mouth ulcers and plants

In my opinion, you have to be careful about the use of plants in your care, especially when you’re taking a treatment like chemotherapy.

Indeed, everything that comes from nature, is not necessarily good for health.

There is a very good website that includes all the features and contraindications of medicinal plants.

Before any use of plants to treat an ulcer, you must have the advice of your doctor.


Honey to cure the canker sores ?

Honey is sometimes stated to be « grandmother’s » remedy for healing the mouth ulcer and facilitating the healing of the blister.

In my opinion, it’s better to be careful with this « miracle solution » because honey contains sugar that boosts the acidity of the mouth… which is one of the causes of appearance of ulcers.

So, as often before testing oneself, the ideal is to have the medical advice of your doctor regarding this natural treatment.



Mouth ulcers and homeopathic remedies

France is the country where homeopathy is widespread, as is India.

This form of complementary medicine was founded by a German physician, Samuel HAHNEMANN with his essential work, published in 1810, the organon of rational medicine.

Scientific studies that have tried to demonstrate the effectiveness of homeopathy have not been very conclusive.

However, patients who use homeopathy are relieved, especially to treat conditions of everyday life.

The best homeopathic remedy for mouth ulcers is granular borax, to be taken three times a day, as soon as the symptoms are felt and before the appearance of the blister.


In chemotherapy, it’s necessary to think of using a mouthwash after having taken granules to eliminate the traces of sugars contained in the granule.


Some patients add 20 drops of calendula mother tincture to their mouthwash. Talk to your doctor to get his opinion about it.


In addition, the ratanhia toothpaste can sometimes calm inflammation of the mouth.


Anaesthetic products and mouth ulcers

Canker sores can be extremely painful. To relieve yourself, ask your doctor if you can use anaesthetic paste (Dolodent ©) such as those used with babies during their dental surges.

In addition, your doctors may prescribe anaesthetic spray containing lidocaine. They are available, but please know that they themselves can have side effects. You must read the package leaflet before using them.

In the same spirit, there are gingival pastes to put on the mouth ulcer, to be found in the pharmacy. This helps to form a barrier between the food and the wound made by the blister or the mouth ulcer.


Besides, there are vaporizers and lozenges containing local antiseptics. Before using them, talk to your doctor to see if there are any contraindications to their use.



To conclude, mouth ulcers are part of the daily lives of many people and particularly affect people undergoing treatment for a serious illness such as cancer.

A medical accompaniment is always desirable to cure its lesions and wounds of the mouth, there are many tips and tricks, often natural to relieve the people who suffer from it.

And especially since canker sores can be so painful, that having meals can become very difficult, increase the risk of undernutrition which is a medical emergency during cancer treatments.


Credit photo : Artsem Martysiuk – Fotolia

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