Mouth Dryness or Thick Saliva

Radiation therapy to the head and neck areas, some types of chemo, certain other medicines, and dehydration can cause dry mouth or thick saliva. The glands that make saliva can become irritated and make less saliva, or your saliva can become very thick and sticky. Dryness can be mild or severe. A dry mouth can increase your risk of cavities and mouth infection. If you smoke, chew tobacco, or drink alcohol, the dryness can be worse.

If you have either of these side effects, drink plenty of fluids throughout the day and eat moist foods as much as possible. Also brush your teeth and rinse your mouth often with a baking soda, salt, and water solution to help keep it clean and prevent infection (recipe follows).

What to look for

  • Dried, flaky, whitish saliva in and around the mouth
  • Thick saliva that’s more like mucus and that sticks to lips when you open your mouth
  • Trouble swallowing foods or thick liquids
  • Mouth breathing (dries out the mouth and throat)
  • Burning tongue
  • Bits of food or other matter on the teeth, tongue, and gums
  • Tongue surface looks ridged or cracked

What the patient can do

  • Rinse your mouth every 2 hours with a salt and soda solution. You can make this solution by adding 1 teaspoon of salt and 1 teaspoon of baking soda to 1 quart of warm water. Shake the solution before each use, then swish it and spit. Do not swallow it.
  • Take small bites, and chew your food well.
  • Sip liquids with meals to moisten foods and help with swallowing.
  • Add liquids (such as gravy, sauce, milk, and yogurt) to solid foods.
  • Try ice chips, sugarless hard candies, and sugarless chewing gum.
  • Keep cold water nearby for frequent sips between meals and mouth rinses.
  • Rinse or spray mouth often using artificial saliva, which is sold in drugstores.
  • Use petroleum jelly, cocoa butter, or a mild lip balm to keep lips moist.
  • Avoid hot, spicy, or acidic foods.
  • Avoid chewy candies, tough meats, pretzels and chips, and hard raw fruits or vegetables.
  • Avoid alcohol, including store-bought mouthwashes.
  • Avoid tobacco
  • Suck on sugarless candy or chew sugarless gum to stimulate saliva. Citrus, cinnamon, and mint flavors often work well.
  • Use a cool mist humidifier to moisten room air, especially at night. (Be sure to keep the humidifier clean to avoid spreading bacteria or mold in the air.)
  • Fresh pineapple or papaya may help to thin saliva, but only try this if your mouth is not sore.
  • Nutritional supplements, like liquid meal replacements, may be helpful. If you can’t get enough calories and nutrition through solid foods, you may need to use liquid supplements for some time. Talk to your cancer care team about this.

What caregivers can do

  • Offer small, soft meals with extra sauce or dressings for dipping.
  • Offer ice cream, gelatin desserts, ice chips, and frozen drinks.
  • Keep liquids nearby for frequent sipping.
  • Help the patient track their fluid intake, and encourage them to take in 2 to 3 quarts of liquid each day, if the cancer team approves. Ice, ice cream, sherbet, popsicles, and gelatin count as liquids.

Call the cancer team if the patient:

  • Has a dry mouth for more than 3 days
  • Can’t take medicines or swallow pills
  • Can’t drink or eat
  • Has dry, cracked lips or mouth sores
  • Has trouble breathing


The American Cancer Society medical and editorial content team

Our team is made up of doctors and oncology certified nurses with deep knowledge of cancer care as well as journalists, editors, and translators with extensive experience in medical writing.

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Last Medical Review: June 8, 2015 Last Revised: July 29, 2019

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