Xerostomia, commonly called dry mouth, occurs when the salivary glands do not make enough saliva, or spit, to keep the mouth moist. Because saliva is needed for chewing, swallowing, tasting, and talking, these activities may be more difficult with a dry mouth.
Signs and symptoms
The signs and symptoms of dry mouth include the following:
- A sticky, dry feeling in the mouth
- Thick, stringy saliva
- Pain or a burning sensation in the mouth or on the tongue
- Cracks in the lips or at the corners of the mouth
- A dry, tough tongue
- Difficulty chewing , tasting, or swallowing
- Difficulty talking
In addition, dry mouth often causes dental problems . Saliva helps maintain a healthy balance of bacteria in the mouth. Without enough saliva, the bacteria and other organisms in the mouth grow too quickly. This can cause sores and mouth infections, including an infection called thrush that is caused by an overgrowth of yeast. Saliva also washes away acids and food particles left in the mouth after eating, which means that a lack of saliva can cause gum disease and cavities, which is tooth decay. Dry mouth may make it difficult to wear dentures, as well.
Chemotherapy or radiation treatments cause dry mouth by damaging the salivary glands. Chemotherapy causes dry mouth by making saliva thicker, which is usually a temporary symptom that clears up about two to eight weeks after treatment ends.
Radiation therapy to the head, face, or neck may also cause dry mouth. It can take six months or longer for the salivary glands to start producing saliva again after the radiation therapy ends. Although some people experience improvement during the first year after radiation treatment, many people will continue to experience some level of long-term dry mouth, especially if the radiation therapy was directed at the salivary glands.
In addition, a disease called graft-versus-host disease, in which cells transplanted from a donor recognize the patient's body as foreign and attack it, may cause dry mouth and mouth sores. Antidepressants, medications called diuretics that increase urination, and some painkillers can cause dry mouth. Or, dry mouth can result from a mouth infection such as thrush or dehydration.
Managing dry mouth
Relieving side effects, also called symptom management, palliative care , or supportive care, is an important part of cancer care and treatment. Talk with your health care team about any symptoms you experience, including any new symptoms or a change in symptoms.
Although dry mouth cannot be prevented, some treatments can help. These include:
- Medication that prevents or lessens the side effects of radiation treatment, such as amifostine (Ethyol)
- Saliva substitutes and mouth rinses with hyetellose, hyprolose, or carmellose
- Medications that stimulate the salivary glands, such as pilocarpine (Salagen) or cevimeline (Evoxac)
- Other ways to stimulate the salivary glands, such as sucking on sugar-free candy or chewing sugarless gum
The following tips may help with the management of dry mouth and the prevention of dental problems:
- Visit a dentist before starting radiation treatment or chemotherapy to check the health of your mouth and teeth. It’s important to schedule this as soon as you can because if you need to have teeth removed, it should be done at least three weeks before treatment begins so your mouth has time to heal.
- Brush your teeth after each meal and at bedtime with a soft-bristle toothbrush and fluoride toothpaste. Soak the brush in warm water to make the bristles even softer.
- Floss gently once a day.
- Rinse your mouth four to six times a day, especially after meals, with salt and baking soda. Try a solution of half a teaspoon of salt and half a teaspoon of baking soda in one cup of warm water.
- When radiation therapy starts, use fluoride rinses and gels. These are an important part of caring for the health of your mouth during cancer treatment.
- Drink sips of water throughout the day, and use artificial saliva to moisten the mouth.
- Avoid mouthwashes and other dental products that contain alcohol. Products designed for people with dry mouth are available without a prescription.
- Use a cool mist humidifier, especially at night.
In addition, some dentists may prescribe medication to increase saliva production or rinses to fight infections in the mouth.
Consider the following tips for eating with a dry mouth:
- Drink at least eight cups of water a day. Carrying a bottle of water may help you drink enough.
- Avoid alcohol, drinks with caffeine (such as coffee, tea, and cola), and acidic juices.
- Eat soft, moist foods that are cool or at room temperature.
- Moisten dry foods with broth, sauces, butter, or milk.
- Avoid dry, coarse, or hard foods.
- Avoid acidic or spicy foods that burn the mouth.
- Do not smoke or chew tobacco.
- Avoid sticky, sugary foods and drinks.
Taste Changes 
Side Effects