What you can do at home for a mouth sore, and what to avoid

Most mouth sores heal on their own within 1 to 2 weeks, but how you care for them in the meantime changes how much pain and discomfort you have. In Korea, the stomatitis care recommended by the National Health Information Portal of the Korea Disease Control and Prevention Agency (KDCA, 질병관리청) comes down to eating well, keeping the mouth and teeth clean, quitting tobacco and alcohol, and avoiding irritating foods. However, care at home only eases symptoms, so if it lasts long or keeps recurring, you need an exam.

Published 2026-11-08 · Updated 2026-11-08 · DentalStatics editorial team

Key facts

Basic everyday care	Adequate nutrition, oral hygiene, dental care, quitting smoking and drinking, avoiding irritating foods (source: KDCA National Health Information Portal)
Foods to avoid	Nuts, snacks, and irritating foods that are salty, spicy or sour (source: Seoul National University Hospital)
Fluid intake	1.5 to 2 L a day, split over several times (source: KDCA National Health Information Portal)
Controlling pain before meals	When pain is severe, a topical anesthetic can be used before meals (source: Seoul National University Hospital)
Caution with ointment	Steroid ointment is best avoided for hand-foot-and-mouth disease (source: KDCA National Health Information Portal)

How should I brush when I have a mouth sore?

If you skip brushing because it hurts, food and bacteria stay in the mouth. Keeping the mouth clean is a care principle that both the National Health Information Portal and Seoul National University Hospital's medical information stress in common, and Seoul National University Hospital's medical information also advises regular scaling and use of an oral rinse as prevention.

Brush around the ulcer area lightly with a soft-bristled toothbrush, and if the toothbrush hurts too much there, rinse that part with water instead. Seoul National University Hospital's medical information advises being careful not to injure the lining while brushing, so avoid scrubbing hard.

If an oral rinse stings the ulcer badly, stop using it for a while and discuss with the dentist which product suits you. After brushing, rinse well with water so toothpaste ingredients do not stay on the ulcer for long.

What should I eat and what should I avoid with a mouth sore?

Seoul National University Hospital's medical information advises avoiding strongly irritating foods such as nuts, snacks, and salty, spicy and sour foods, and choosing healthy foods. The same material names hot food as an aggravating factor of aphthous symptoms. If you eat less because of pain, you can become short of nutrition, so do not skip meals, even if only with soft foods. The methods below help when eating.

Choose soft, mild foods such as porridge, steamed egg and tofu
Let hot soups and drinks cool before having them
Cut food small to reduce the area that touches the ulcer
Talk less during meals and chew slowly to protect the cheek and tongue
When pain is severe, use the prescribed anesthetic medicine before meals

How do I use mouthwash or ointment for a mouth sore?

The drugs the National Health Information Portal introduces as usable for aphthous stomatitis include mouthwash that reduces pain, mouthwash that reduces bacteria, steroid ointment that calms inflammation, and medicine that covers and protects the lining. These drugs suit some causes and not others, so if it is a first mouth sore or looks different from usual, use them after getting them prescribed at an exam.

The same material advises that steroid ointment is best avoided for hand-foot-and-mouth disease. If a child's mouth is sore and there are also blisters on the hands and feet, see a doctor before applying any ointment you have at home. Wash your hands before applying ointment, and keep to the prescribed frequency and period.

Whether you can eat or rinse your mouth right after applying differs by drug, so ask when it is prescribed. Avoid sharing someone else's leftover medicine at home.

How do I manage dry mouth and daily habits?

The National Health Information Portal explains that dry mouth affects oral diseases such as ulcers of the oral lining. The same material recommends drinking about 1.5 to 2 L of water a day split over several times, and advises avoiding alcohol, tobacco and caffeine, which dry the mouth further. If the indoor air is dry, humidifying so the mouth does not dry out is also an option.

The state of the body also affects recovery. Seoul National University Hospital's medical information recommends reducing stress and overwork and getting enough nutrition, and the National Health Information Portal advises that if the stomatitis arose from a vitamin B12 or iron shortage, making up for it can help recovery.

When should I get care instead of managing at home?

Most cases improve with care at home, but in the cases below, get care instead of continuing only the home care. The National Health Information Portal advises getting examined at a nearby medical institution if the lesion persists or recurs. At the visit, telling them the medicines and care methods you tried at home and their effect helps decide the next treatment.

When there is an ulcer that has not healed in more than 2 to 3 weeks
When the ulcer keeps getting bigger or feels firm to the touch
When mouth sores recur several times in a year
When you have a fever and have trouble swallowing water or food
When lesions appear on the skin outside the mouth, the eyes or the genitals

Common myths and facts

Myth: It is better to stop brushing when you have a mouth sore.

Seoul National University Hospital's medical information advises keeping the mouth clean and regular scaling as ways to prevent stomatitis. Rather than skipping brushing, choose a way of brushing gently around the ulcer.

Myth: Any ointment is fine to put on a mouth sore.

The National Health Information Portal advises that steroid ointment is best avoided for hand-foot-and-mouth disease. The suitable drug differs by cause, so for a first mouth sore use medicine after an exam.

Frequently asked questions

What should I do about alcohol and cigarettes when I have a mouth sore?

The National Health Information Portal includes quitting smoking and drinking in everyday care for stomatitis. Alcohol can irritate the ulcer and dry the mouth, and smoking is also a local cause of aphthae named by Seoul National University Hospital's medical information. If ulcers form often, it is good to start quitting smoking now. If it is hard to quit alone, you can get help such as a public health center's quit-smoking clinic.

What supplements should I take for mouth sores?

Seoul National University Hospital's medical information advises taking separately the vitamin B12, iron and folate that meals alone do not supply. Which ingredient is lacking differs by person, so if mouth sores are frequent, it is good to check with a blood test before choosing. If you already take supplements, tell the clinician the ingredients and doses at the visit.

What should I do if my child can't eat because of a mouth sore?

When mouth pain keeps a child from eating, the priority is to prevent dehydration by giving cool or lukewarm water in small amounts often. The National Health Information Portal explains that a child with herpetic stomatitis who cannot eat well may need hospital admission if dehydration develops, so if urine output drops or the child becomes listless, get care right away.

When is the best time to start using mouth sore ointment?

How often and how long to apply differs by drug, so follow the instructions given when prescribed. Seoul National University Hospital's medical information explains that the earlier you start, the better it is for shortening the time of illness, so it is good to get an exam when the tingling and a small ulcer begin to show.

Is there a way to heal a mouth sore faster?

Most mouth sores heal only as time passes, and official sources do not present any home method that surely speeds it up. The realistic approach is to keep to the oral hygiene, nutrition, quitting smoking and drinking, and avoiding irritating foods recommended by the National Health Information Portal, and if pain is severe, to start the medicine prescribed after an exam early.

References

Korean version →