Cancer Treatment - Sore Mouth, Gums or Throat

Cancer treatment sore mouth gums or throat

Cancer Treatment - Sore Mouth, Gums or Throat

Good oral care is important during cancer treatment. Some anticancer drugs can cause sores in the mouth and throat, a condition called stomatitis or mucositis. Anticancer drugs also can make these tissues dry and irritated or cause them to bleed. Patients who have not been eating well since beginning chemotherapy are more likely to get mouth sores.

Mouth sores, tender gums, and a sore throat or esophagus often result from radiation therapy, chemotherapy, or infection. If you are under treatment for cancer and have a sore mouth or gums, see your doctor to be sure the soreness is a treatment side effect and not an unrelated dental problem. The doctor may be able to give you medicine that will control mouth and throat pain. Your dentist also can give you tips for the care of your mouth.

In addition to being painful, mouth sores can become infected by the many germs that live in the mouth. Every step should be taken to prevent infections, because they can be hard to fight during chemotherapy and can lead to serious problems.

How can I keep my mouth, gums, and throat healthy?

  • Talk to your doctor about seeing your dentist if possible at least several weeks before you start chemotherapy. You may need to have your teeth cleaned and to take care of any problems such as cavities, gum abscesses, gum disease, or poorly fitting dentures. Ask your dentist to show you the best ways to brush and floss your teeth during chemotherapy. Chemotherapy can make you more likely to get cavities, so your dentist may suggest using a fluoride rinse or gel each day to help prevent decay.
  • Brush your teeth and gums after every meal. Use a soft toothbrush and a gentle touch. Brushing too hard can damage soft mouth tissues. Ask your doctor, nurse, or dentist to suggest a special toothbrush and/or toothpaste if your gums are very sensitive. Rinse with warm salt water after meals and before bedtime.
  • Rinse your toothbrush well after each use and store it in a dry place.
  • Avoid mouthwashes that contain any amount of alcohol. Ask your doctor or nurse to suggest a mild or medicated mouthwash that you might use. For example, mouthwash with sodium bicarbonate (baking soda) is non-irritating.

If you develop sores in your mouth, tell your doctor or nurse. You may need medicine to treat the sores. If the sores are painful or keep you from eating, you can try these ideas:

How can I cope with mouth sores?

  • Ask your doctor if there is anything you can apply directly to the sores or to prescribe a medicine you can use to ease the pain.
  • Eat foods cold or at room temperature. Hot and warm foods can irritate a tender mouth and throat.
  • Eat soft, soothing foods, such as ice cream, milkshakes, baby food, soft fruits (bananas and applesauce), mashed potatoes, cooked cereals, soft-boiled or scrambled eggs, yogurt, cottage cheese, macaroni and cheese, custards, puddings, and gelatin. You also can puree cooked foods in the blender to make them smoother and easier to eat.
  • Avoid irritating, acidic foods and juices, such as tomato and citrus (orange, grapefruit, and lemon); spicy or salty foods; and rough or coarse foods such as raw vegetables, granola, popcorn, and toast.

How can I cope with mouth dryness?

  • Ask your doctor if you should use an artificial saliva product to moisten your mouth.
  • Drink plenty of liquids.
  • Ask your doctor if you can suck on ice chips, popsicles, or sugarless hard candy. You can also chew sugarless gum. (Sorbitol, a sugar substitute that is in many sugar-free foods, can cause diarrhea in many people. If diarrhea is a problem for you, check the labels of sugar-free foods before you buy them and limit your use of them.)
  • Moisten dry foods with butter, margarine, gravy, sauces, or broth.
  • Dunk crisp, dry foods in mild liquids.
  • Eat soft and pureed foods.
  • Use lip balm or petroleum jelly if your lips become dry.
  • Carry a water bottle with you to sip from often.

Certain foods will irritate an already tender mouth and make chewing and swallowing difficult. By carefully choosing the foods you eat and by taking good care of your mouth, teeth, and gums, you can usually make eating easier. Here are some suggestions that may help:

  • Try soft foods that are easy to chew and swallow such as: milkshakes, bananas, applesauce, fruit nectars, cottage cheese, yogurt, mashed potatoes, puddings, scrambled eggs, and oatmeal.
  • Avoid foods or liquids that can irritate your mouth such as: oranges, grapefruits, lemons, tomato sauces or juice, spicy or salty foods, raw vegetables, granola, and commercial mouthwashes that contain alcohol.
  • Cook foods until they are soft and tender.
  • Cut foods into small pieces.
  • Use a blender or food processor to puree your food.
  • Mix food with butter, margarine, thin gravy, or sauce to make it easier to swallow.
  • Use a straw to drink liquids.
  • Use a smaller-than-usual spoon, such as a baby spoon.
  • Try foods cold or at room temperature. Hot foods can irritate a tender mouth and throat.
  • Try drinking warm bouillon; it can soothe throat pain.
  • Try sucking on ice chips though often things that are too cold or too hot may be uncomfortable. Experiment.
  • If swallowing is hard, tilting your head back or moving it forward may help.
  • If your teeth and gums are sore, your dentist may be able to recommend a special product for cleaning your teeth.
  • Rinse your mouth often with water to remove food and bacteria and to promote healing.
  • Ask your doctor about anesthetic lozenges and sprays that can numb your mouth and throat long enough for you to eat meals.

For more information about cancer therapy side effects, and coping with them, please read the  "Chemotherapy and Cancer Treatment, Coping with Side Effects" article.



  1. MedicineNet


Medically reviewed by Jay Zatzkin, MD; Board Certification in Internal Medicine and Oncology July 13, 2017

National Cancer Institute (

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