Mucositis (Mouth Sores) & Oral Care Tip Sheet

Author: Marisa Healy, BSN, RN
Last Reviewed: October 03, 2022

What is Mucositis?

Mucositis is inflammation of the lining of your mouth and throat. It can be anything from a red, sore mouth and/or gums to very painful open sores. These sores can make it hard for you to eat. Other names for mucositis are mouth sores, oral mucositis, or esophagitis.

Radiation therapy to your head and neck area and some types of chemotherapy can cause mucositis. Other causes of mucositis are:

  • Infection.
  • Dehydration (not enough water in your body).
  • Poor mouth care.
  • Oxygen therapy.
  • Drinking too much alcohol.
  • Using tobacco.
  • Not having enough protein in your diet.

Mucositis can cause pain, problems with nutrition and being unable to eat, and a higher chance of infection because of the open sores. It can affect your quality of life. Your provider may need to lower your chemotherapy dose so that the sores can heal (called a dose-limiting effect).

Signs and symptoms of mucositis are:

  • Red, shiny, or swollen mouth and gums.
  • Blood in the mouth.
  • Sores in the mouth, on the gums, or tongue.
  • Soreness or pain in the mouth or throat.
  • Having a hard time swallowing or talking.
  • Feeling of dryness, mild burning, or pain when eating food.
  • Soft, white-ish patches or pus in the mouth or on the tongue.
  • More mucus or thicker saliva in the mouth.

Talk to your healthcare team about your risk of getting mucositis. If you are at risk for mucositis, your care team should teach you oral and mouth care to help prevent mucositis.

Special care should be taken to help the mouth and throat heal if mucositis does happen. There have been studies about the use of oral cryotherapy. Oral cryotherapy is the practice of eating ice chips and drinking ice water during your infusion of some types of chemotherapy to prevent mucositis. Ask your provider if this is right for you and the type of therapy you are receiving.

What does a good oral (mouth) care plan look like?

  • Check the whole mouth twice a day using a small flashlight and tongue blade (tongue depressor). If you wear dentures, remove them and look under the plates. Report any changes to your provider.
  • Rinse your mouth (swish, lightly gargle and spit) before and after meals and at bedtime with either:
    • Salt water (1 tsp of table salt to 1 quart [32 oz.] of water) or;
    • Salt and Soda rinse (1 tsp of salt and 1 tsp of baking soda in 1 quart [32 ounces] of warm water).
  • Use a soft-bristle toothbrush after meals and at bedtime. Soaking in hot water can make the brush bristles softer. If the brush causes pain, toothettes may be used (but these are not as effective as a soft or super soft brush).
  • Use non-abrasive toothpaste (or mix 1 tsp baking soda in 2 cups water). Avoid toothpastes with whiteners or other additives.
  • Keep lips moist with moisturizers (like Chap stick® or Blistex®).
  • Do not use products that irritate the mouth and gums:
    • Do not use commercial mouthwashes and those with alcohol.
    • Try not to use dental floss often. DO NOT use floss with platelets below 40,000. Your provider will keep you updated about your blood levels.
    • Do not use lemon or glycerin swabs or toothbrushes without soft bristles.
  • Make changes to your diet to decrease pain and discomfort, and to help with healing of mouth sores.
    • Increase your fluid intake. Try to drink 3 quarts (about 12 cups) of fluid per day, unless your provider tells you not to do so.
    • Eat foods high in protein such as dried beans, poultry, eggs, peanut butter, meat, fish, and dairy products, such as milk, cheese and yogurt (Greek yogurt is higher in protein than others). Nutritional supplement shakes like Ensure® and Boost® can also provide calories and protein.
    • Stay away from hot, spicy, greasy, or fried foods.
    • Do not drink alcohol.
    • Stay away from citrus fruits and juices, such as oranges, lemons, limes, and tomatoes as these may be too acidic. Try apricots, pears, or peaches instead.
    • Do not eat hard or coarse foods, such as crusty bread, crackers, raw vegetables, potato chips, tortilla chips, or pretzels.
    • Do not drink carbonated beverages like soda and seltzer.
    • Try soft foods like puddings, jello, soups, etc.
    • Cold treats like popsicles and water ice can be soothing to mouth sores.
    • Eat whenever you are hungry, even if it's not mealtime.
    • Eat smaller, more frequent meals throughout the day, rather than three large meals. Create a nice environment when eating to stimulate (rev up) your appetite.
  • If you wear dentures:
    • Clean dentures every day.
    • Remove at night and whenever possible to expose gums to air.
    • Loose-fitting dentures can irritate the mouth and gums and should not be worn.
    • Do not wear dentures if mouth sores are severe.
  • Do not smoke cigarettes, cigars, or pipes. Do not use smokeless tobacco (chewing tobacco, snuff).

When should I call my provider?

Mouth sores should not be ignored, since they can cause you to eat and drink less, can be a source of infection, and can cause pain and discomfort. Call your provider right away if you have one or more of the following:

  • Redness or shininess in the mouth that lasts for more than 48 hours.
  • When you first notice any type of cut or sore in the mouth.
  • Bleeding gums.
  • Have pain or a hard time with eating or swallowing.
  • Oral temperature above 100.4°F (38.0°C), chills, or sweats.
  • Weight loss of 5 pounds or more since the mouth sores began.

How are mouth sores treated?

Mouth sores often must heal on their own. Good mouth care can help speed the healing process. If mouth pain is making it hard to eat and swallow, your provider may prescribe a mouth rinse to numb the mouth for a short period of time, or an oral pain medication. If weight loss is a problem, you may be referred to a dietician. Your care team may decide to delay further treatments until the mouth sores have healed.

If you have any questions about mouth sores, or need more information and direction, ask your provider.

The Oral Cancer Foundation. (2020). Mucositis. Retrieved from

U.S. Department of Health and Human Services National Institutes of Health. (2020). Oral mucositis- self-care. Retrieved from

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