Mouth Dryness or Thick Saliva
Dry mouth, or xerostomia, develops when your body doesn’t make enough saliva (spit) or when saliva becomes very thick.
What causes dry mouth or thick saliva?
The most common cause of dry mouth is radiation therapy to the head and neck area. Some types of chemotherapy, certain other medicines, and dehydration can also cause dry mouth. The salivary glands can become damaged and make less saliva, or your saliva can become very thick and sticky.
Having a dry mouth or thick saliva can increase your risk of cavities and mouth infections. Smoking, chewing tobacco, and drinking alcohol can make dryness worse.
Dry mouth may last for a little while, such as during chemotherapy. But sometimes, dry mouth might be permanent. This happens most often with high doses of radiation to the head and neck area.
Dry mouth can also be caused by:
- Graft-versus-host disease, which sometimes happens with a bone marrow or stem cell transplant
- Antidepressants
- Medicines called diuretics, which make your body get rid of fluids
- Some pain medicines
- Medicines for nausea and vomiting (antiemetics)
- Mouth infections
- Antihistamines
Symptoms of dry mouth
- A sticky, dry feeling in the mouth
- Thick, stringy saliva that sticks to lips when you open your mouth
- Pain or burning in the mouth or on the tongue
- Cracks in the lips or at the corner of your mouth
- Ridges or cracks on your tongue
- Trouble chewing, tasting, or swallowing
- Trouble talking
Having a dry mouth makes you more likely to get an infection, gum disease, and tooth decay (cavities).
Treatment for dry mouth or thick saliva
Many treatments for dry mouth are suggested for people getting radiation for head and neck cancer. They may or may not help with dry mouth from other types of treatments or in other types of cancer. Some of these treatments include:
- Medicines such as pilocarpine, cevimeline, or bethanechol
- Acupuncture to improve the symptoms of dry mouth
- Transcutaneous electrical nerve stimulation (TENS) to help the glands make more saliva
There are also ways to give radiation treatment that might protect the salivary glands. Ask your radiation oncology doctor if these might be options for you.
Tips for managing dry mouth
Keep your mouth clean
- Brush your teeth each time you eat and at bedtime. Use a soft toothbrush.
- Rinse your mouth every 2 hours with water or a bland mouth rinse. Some people find baking soda, salt water, or saline rinses helpful. Ask your cancer care team what they suggest.
- Don’t use store-bought mouthwashes that have alcohol in them.
Keep your mouth moistened
- Try to drink at least eight 8-ounce glasses of fluids each day.
- Keep water nearby for frequent sips between meals and mouth rinses.
- Try artificial saliva as needed. It comes as rinses, gums, sprays, or tablets which can be found in drugstores.
- Suck on sugarless candy or chew sugarless gum to help increase saliva flow. Citrus, cinnamon, and mint flavors often work well.
- Use a water-based lip balm to keep lips moist.
- Use a cool mist humidifier to make room air less dry, especially at night. (Be sure to keep the humidifier clean to avoid spreading bacteria or mold in the air.)
- Avoid drinking alcohol or caffeine
- Don’t smoke or chew tobacco.
Eating tips
- Take small bites and chew your food well.
- Sip liquids with meals if you need help swallowing.
- Add liquids (such as gravy, sauce, milk, and yogurt) to solid foods.
- Avoid hot, spicy, or acidic foods.
- Avoid acidic juices, such as tomato, orange, and apple juice.
- Avoid tough meats, pretzels and chips, and hard, raw fruits or vegetables.
- Avoid sticky, sugary foods and drinks.
- Ask your cancer care team if nutritional supplements might be helpful.
Call your doctor or cancer care team if you
- Can't eat or drink
- Can’t take medicines or swallow pills
- Have dry, cracked lips or mouth sores
- Have new mouth dryness for more than 3 days
- Written by
- References
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 editors and translators with extensive experience in medical writing.
Alhejoury HA, Mogharbel LF, Al-Qadhi MA, et al. Artificial Saliva for Therapeutic Management of Xerostomia: A Narrative Review. J Pharm Bioallied Sci. 2021;13(Suppl 2):S903-S907.
American Society of Clinical Oncology. Dry Mouth or Xerostomia. Accessed at cancer.net. Content is no longer available.
Freedman K & Hole A. Gastrointestinal complications. In: Eggert JA, Byar KL & Parks LS, ed. Cancer Basics. Oncology Nursing Society; 2022: 313-331.
Mercadante V, Jensen SB, Smith DK, et al. Salivary Gland Hypofunction and/or Xerostomia Induced by Nonsurgical Cancer Therapies: ISOO/MASCC/ASCO Guideline. J Clin Oncol. 2021;39(25):2825-2843.
Ni X, Tian T, Chen D, et al. Acupuncture for Radiation-Induced Xerostomia in Cancer Patients: A Systematic Review and Meta-Analysis. Integr Cancer Ther. 2020;19:1534735420980825.
Roesser KA. Stomatitis/Xerostomia. In: Camp-Sorrel D, Hawkins RA, Cope DG, eds. Clinical Manual for the Advanced Practice Nurse. Oncology Nursing Society; 2022: 77-83.
Last Revised: June 26, 2024
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