Mouth and Throat Problems and Cancer Treatment
A plain-language explanation of mouth and throat problems during cancer treatment—what causes them, which problems may occur, and ways to prevent and manage them—based on National Cancer Institute resources.
Source: National Cancer Institute · NCI reviewed 2021-09-24 · Verified 2026-07-02
The 30-second version
Cancer treatments may cause mouth, throat, and dental problems. Radiation therapy to the head and neck, some chemotherapy, and some immunotherapy can harm the mouth, throat, and lips. Problems can include changes in taste, dry mouth, mouth sores, and swallowing trouble. They are more serious when they get in the way of eating and drinking, so tell your team about pain or fever.
Key takeaways
- Cancer treatments may cause mouth, throat, and dental problems.
- Radiation therapy to the head and neck, some chemotherapy, and some immunotherapy can harm the mouth, throat, and lips.
- Problems may include taste changes, dry mouth, infections and mouth sores, pain, sensitivity, swallowing trouble, and tooth decay.
- Mouth problems are more serious when they interfere with eating and drinking, which can lead to dehydration or malnutrition.
- Getting a dental check-up before treatment and cleaning your mouth daily can help prevent problems.
- Call your doctor for mouth or throat pain that makes it hard to eat, drink, or sleep, or for a fever of 100.5 degrees F (38 degrees C) or higher.
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The full explanation.
What causes mouth and throat problems
Cancer treatments may cause mouth, throat, and dental problems. Radiation therapy to the head and neck may harm the salivary glands and tissues in your mouth, and may make it hard to chew and swallow safely. Some types of chemotherapy and immunotherapy can also harm cells in your mouth, throat, and lips. Drugs used to treat cancer and certain bone problems may cause oral problems too.
What problems may occur
Mouth and throat problems may include:
- changes in taste (dysgeusia) or smell
- dry mouth (xerostomia)
- infections and mouth sores
- pain or swelling in your mouth (oral mucositis)
- sensitivity to hot or cold foods
- swallowing problems (dysphagia)
- tooth decay (cavities)
When mouth problems are serious
Mouth problems are more serious if they interfere with eating and drinking, because they can lead to dehydration and malnutrition.
Call your doctor or nurse if you have pain in your mouth, lips, or throat that makes it difficult to eat, drink, or sleep, or if you have a fever of 100.5 degrees F (38 degrees C) or higher.
Ways to prevent mouth and dental problems
Your doctor or nurse may advise you to take these and other steps:
- Get a dental check-up before starting treatment. Visit your dentist for a cleaning and check-up, tell them about your cancer treatment, and try to complete any dental work before treatment starts.
- Check and clean your mouth daily. Check your mouth every day for sores or white spots, and tell your doctor or nurse as soon as you notice any changes. Rinse throughout the day with a solution of warm water, baking soda, and salt—ask your nurse to write down the recipe recommended for you. Gently brush your teeth, gums, and tongue after each meal and before bed using a very soft toothbrush or cotton swabs. If you are at risk of bleeding, ask whether you should floss.
Ways to manage mouth problems and taste changes
Your healthcare team may suggest these steps:
- For a sore mouth or throat: Choose foods that are soft, wet, and easy to swallow, and soften dry foods with gravy, sauce, or other liquids. Blend foods or make milkshakes to make swallowing easier. Ask about pain medicine, such as lozenges or sprays that numb your mouth. Avoid foods that are crunchy, salty, spicy, or sugary, and avoid alcohol. Don't smoke or use tobacco.
- For a dry mouth: Drink plenty of liquids, because a dry mouth can raise the risk of tooth decay and mouth infections. Sip water often, suck on ice chips or sugar-free hard candy, have frozen desserts, or chew sugar-free gum. Use a lip balm, and ask about saliva substitutes that can coat and moisten your mouth. Acupuncture may also help with dry mouth.
- For taste changes: Food may taste different or bland. It may help to try different foods to find ones that taste best, and cold foods may help. If red meat tastes strange, try other high-protein foods like chicken, eggs, fish, or beans. If foods taste metallic, switch to plastic utensils and non-metal dishes. Marinating foods or adding spices may improve flavor.
Watch instead
Animated lessons are in production. Here’s the planned video slate for this topic — each one will be based on the same NCI-sourced explanation you’re reading.
Mouth and Throat Problems and Cancer Treatment: the quick overview
A one-breath explanation you can watch before an appointment.
Coming soonMouth and Throat Problems and Cancer Treatment, explained simply
The core ideas with friendly animation and plain language.
Coming soonUnderstanding mouth and throat problems and cancer treatment — full lesson
A deeper walkthrough covering the key takeaways and common questions.
Coming soonVideo transcript▾
A full, readable transcript will appear here when the video is published — so the lesson is accessible whether you prefer to watch, listen, or read. For now, the article above is the complete text version.
Suggested animation storyboard▾
- 1Open on a calm title card: "Mouth and Throat Problems and Cancer Treatment" with the Cancer Explained mark.
- 2Narrator reads the 30-second summary while a soft animated diagram builds on screen: "Cancer treatments may cause mouth, throat, and dental problems. Radiation therapy to the head and neck, some chemotherapy, and some immunotherapy can harm the mouth, throat, and lips. Problems can include changes in taste, dry mouth, mouth sores, and swallowing trouble. They are more serious when they get in the way of eating and drinking, so tell your team about pain or fever."
- 3Scene 2: illustrate the idea — "Cancer treatments may cause mouth, throat, and dental problems."
- 4Scene 3: illustrate the idea — "Radiation therapy to the head and neck, some chemotherapy, and some immunotherapy can harm the mouth, throat, and lips."
- 5Scene 4: illustrate the idea — "Problems may include taste changes, dry mouth, infections and mouth sores, pain, sensitivity, swallowing trouble, and tooth decay."
- 6Close on a reminder card: this is educational only; talk with your healthcare team, and a link to the NCI source.
Words to know
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Quick knowledge check
According to this article, which treatment can harm the salivary glands and tissues in the mouth?
Frequently asked questions
▸What causes mouth and throat problems during cancer treatment?
Radiation therapy to the head and neck may harm the salivary glands and tissues in your mouth and make chewing and swallowing hard. Some types of chemotherapy and immunotherapy can also harm cells in your mouth, throat, and lips. Some drugs used for cancer and certain bone problems may also cause oral problems.
▸What kinds of mouth and throat problems may occur?
Problems may include changes in taste or smell, dry mouth, infections and mouth sores, pain or swelling in your mouth (oral mucositis), sensitivity to hot or cold foods, swallowing problems, and tooth decay.
▸When are mouth problems serious?
Mouth problems are more serious if they interfere with eating and drinking, because they can lead to dehydration and malnutrition. Call your doctor or nurse if you have pain in your mouth, lips, or throat that makes it hard to eat, drink, or sleep, or if you have a fever of 100.5 degrees F (38 degrees C) or higher.
▸How can I help prevent mouth and dental problems?
Get a dental check-up before starting treatment, and try to complete any dental work first. Check and clean your mouth daily—look for sores or white spots, rinse with a warm water, baking soda, and salt solution, and gently brush your teeth, gums, and tongue with a very soft toothbrush or cotton swabs. If you are at risk of bleeding, ask whether you should floss.
▸What can help with a sore or dry mouth?
For a sore mouth or throat, choose foods that are soft, wet, and easy to swallow, and ask about pain medicine like lozenges or sprays. For a dry mouth, sip water often, suck on ice chips or sugar-free hard candy, use lip balm, and ask about saliva substitutes. Your healthcare team can suggest steps that fit you.
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Questions to ask your healthcare team
Consider bringing these questions to your next appointment.
- When might these problems start to occur? How long might they last?
- What steps can I take to feel better?
- What medicines can help?
- What symptoms or problems should I call the doctor about?
- What pain medicine or mouthwashes could help me?
- Would you recommend a registered dietitian I could see to learn about good food choices?
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