Overview
Sores can make eating, drinking, and talking hard.
Infections like thrush can happen on top.
Symptoms
Common signs:
- Mouth sores during cancer treatment
- Getting chemotherapy, radiation, or other cancer treatment
Less common
- Mouth pain
- Trouble eating
- White patches
When to get medical care
Causes
Chemo and radiation.
Does it spread or run in families?
- Cancer isn't contagious. You can't catch it from someone.
- Some cases run in families. Ask whether genetic testing makes sense for you.
Who is more likely to get it
- Head and neck radiation
- Some chemo
Possible complications
Diagnosis
Your care team checks your mouth.
The exam
Mouth exam.
Tests
Tests, if needed:
- Swab: For infection.
Treatment
Keep your mouth clean and moist.
Self-care
- Rinse with a mix of salt and baking soda in water several times a day
- Use a soft toothbrush
- Avoid alcohol mouthwash, spicy, acidic, and rough foods
- Suck ice chips during some chemo if advised
- Sip water often
Medicines
Medicines that may help:
| Medicine | Helps with | Good to know |
|---|---|---|
| Numbing rinses | Pain | Prescription. |
| Pain medicine | Severe pain |
OwieClear doesn't give doses: follow the label or your healthcare professional. Medicine names here are examples, not a full list.
Prevention
To lower risk:
- Dental checkup before treatment
Which doctor treats this
- Start with your primary care provider (family doctor or internist).
- They may send you to an oncologist (cancer doctor), often with a surgeon and a radiation doctor.
Living with it
- Keep a simple diary of symptoms, triggers, and medicines to bring to visits.
- Bring a list of your medicines and questions to each visit.
- Ask for a survivorship care plan when treatment ends.
- Gentle activity, like walking, can ease tiredness.
- Long-term illness can affect mood. Tell your doctor if you feel down or anxious.
Support groups and helplines
- American Cancer Society: Help 24/7 at 1-800-227-2345, rides to treatment, and support programs.
- National Cancer Institute: Cancer Information Service: Free answers from cancer information specialists: 1-800-422-6237.
Back to school, work, or sports
- Most people can keep working or going to school.
- Ask about changes that help, like extra breaks or a flexible schedule. Workers may be covered by the ADA. Students may get a 504 plan.
Pregnancy and breastfeeding
- If you're pregnant or planning to be, tell your prenatal provider about this condition.
- Some cancer treatments can harm a baby. Ask about saving eggs before treatment if you want children later.
- Don't start or stop any medicine on your own. Some are safe in pregnancy and some need to be changed.
- Ask before taking any pain reliever. The FDA advises avoiding ibuprofen and naproxen after 20 weeks unless your doctor says to.
- Breastfeeding: Most medicines are fine, but ask. The NIH LactMed database lists what's known about each one.
For caregivers
- Go to visits when you can and take notes.
- Keep a list of medicines, allergies, and doctors in one place.
- Learn the warning signs that need fast care.
- Take breaks and ask for help. Caregivers need care too.
Outlook
Heals after treatment.
Getting ready for your visit
Bring a list of your symptoms and medicines.
Questions to ask
- What rinse should I use?
Research studies
Research studies test new ways to find and treat health problems. Some are looking for volunteers. Talk with your doctor before joining one.
Search ClinicalTrials.gov for studies on Mouth sores from cancer treatment (oral mucositis)
Sources
Last updated 2026-11-12.