Dry mouth and changes in saliva after head and neck cancer treatment

Some treatments for head and neck cancer can make your mouth dry and cause changes in saliva.

Treatments that cause dry mouth or saliva changes

Radiotherapy or chemoradiation to the head or neck can affect your salivary glands. This means you may not make as much spit (saliva) as before and so your mouth may become dry. Your salivary glands may gradually recover after treatment, but your saliva may be thicker and sticky. Some people have a dry mouth permanently. 

If you feel you have too much saliva rather than too little, you may find it difficult to swallow or chew.

If you have thick sticky saliva

Rinsing your mouth regularly and gargling can help with thick saliva. Your head and neck team can give you advice on what type of mouth rinse to use. Rinsing with a weak solution of salt and water may help to loosen thick saliva. Drinking plenty of fluids can also help.

Sometimes a build-up of mucus can cause coughing. This may happen more at night. The hospital or your GP may give you a nebuliser. A nebuliser is a machine that turns a liquid medicine into a fine mist or spray to moisten your mouth and throat. You can then breathe it in through a mask or mouthpiece. The moisture helps to loosen and break up the saliva.

It may help to use the nebuliser throughout your treatment, and for several weeks afterwards. This will depend on how quickly your symptoms improve.

You could also try leaning over a steaming bowl of hot, but not boiling, water with a towel over your head. This can help loosen thick, sticky saliva. It is best to do these 4 to 5 times a day. Using a humidifier may also help make a room less dry.

If you have a dry mouth

Having a dry mouth can be uncomfortable and can affect eating, speaking and sleeping. It also makes you much more likely to get tooth decay. Smoking will dry and irritate your mouth.  It also increases your risk of dental problems. 

If you smoke, it is important to try to stop. Your GP or hospital team can tell you about the support that’s available to help you. Avoid alcohol, especially spirits, which are very irritating to the mouth.

There are different things you can do to help relieve a dry mouth. Always carry a bottle of water with you and take frequent sips. Or, use a water spray instead. You can buy small atomiser spray bottles from most chemists.

If you cannot swallow, your nurse or doctor can give you a nebuliser. 

Rinsing with saltwater

A warm salt water rinse can be soothing if you have a dry mouth. To make the rinse, boil 900ml of water. Let it cool to a warm temperature and then add 1 teaspoon of table salt. Rinse the salt water gently around your mouth. Then spit it out and rinse your mouth with cold or warm water. Try to do this at least 4 times a day. Make a fresh rinse each day.

There are other things you can do to help with a dry mouth.

Other tips to relieve dryness

  • Try sucking ice cubes or sugar-free ice lollies.
  • Avoid drinks that can irritate a dry mouth, such as caffeinated or citrus drinks.
  • Ask your doctor or nurse if any medicines you are taking cause a dry mouth. It may be possible to change the drug or reduce the dose.
  • Use a lip salve to protect your lips.
  • Try using a humidifier in your bedroom at night.
  • Ask your dentist for advice on toothpastes as some contain foaming agents, usually an ingredient called sodium lauryl sulphate (SLS). This can make your mouth dry. But some SLS toothpaste are fluoride-free so are less effective against tooth decay and gum disease.

Eating tips

  • Avoid foods that irritate a dry mouth, such as hard and crunchy foods, spicy, salty foods and citrus fruits.
  • Take sips of water before you take a bite of food. This lubricates the mouth before you start chewing.
  • Eat soft, moist foods with sauces and gravies, such as casseroles and soups.
  • Add moisture and fat to make dry, starchy foods such as bread, biscuits and crackers easier to eat. Use extra oil, salad dressings, yoghurt and mayonnaise or butter to moisten foods.
  • Try rubbing a small amount of olive or sunflower oil onto your gums before a meal. This can make it easier to chew and move foods around the mouth.

Using artificial saliva

You can use artificial saliva to moisten your mouth and throat. It comes in different forms, such as gels, sprays, mouthwashes, pastilles or tablets. Try different types to find out the best for you. Your doctor or dentist can prescribe artificial saliva, or you can buy it from a chemist.

The effect may only last for a short time, so it is best to use it just before eating. For longer-lasting relief at night, try using the gel on your tongue and around the inside of your mouth. This may relieve dryness for up to 5 hours.

If you have dentures, you can use the gel under them to help them feel more comfortable and stay in place. Take your dentures out at night to give your mouth a break from them.

Artificial saliva with added fluoride can also help to protect your teeth. But some saliva products are acidic and can cause tooth decay. If you have your own teeth, make sure you use one that is pH-neutral.

This table has more information about artificial saliva products for a dry mouth.

Stimulating saliva

Treatments that stimulate saliva may help if some of your salivary glands still work or the damage to your glands is temporary. You can buy these products online.

  • Sugar-free gum may help stimulate saliva. Some gums (such as Spry® gum) contain xylitol, a low-calorie sweetener, which can also help reduce tooth decay.
  • XyliMelts® (discs you stick to your gums, teeth or dentures) slowly releases xylitol. which helps stimulate saliva to relieve dryness.

Some sugar-free boiled sweets also stimulate saliva. Choose ones that are sugar-free to help protect your teeth.

About our information

  • References

    Below is a sample of the sources used in our late effects of head and neck cancer treatment information. If you would like more information about the sources we use, please contact us at cancerinformationteam@macmillan.org.uk

    Nilsen M L, Belsky MA et al. Late and long term treatment-related effects and survivorship for head and neck cancer patients. Current treatment options in oncology. 2020. Volume 21. Issue 12.

    Machiels J.-P, Leemans C. R. et al. Squamous cell carcinoma of the oral cavity, larynx, oropharynx and hypopharynx. EHNS-ESMO-ESTRO Clinical Practice Guidelines for diagnosis, treatment and follow-up. Annals of Oncology, 2020. Volume 31, Issue 11, Pages 1462-1475.

  • Reviewers

    This information has been written, revised and edited by Macmillan Cancer Support’s Cancer Information Development team. It has been reviewed by expert medical and health professionals and people living with cancer. It has been approved by Senior Medical Editor, Dr Chris Alcock, Consultant Clinical Oncologist.

    Our cancer information has been awarded the PIF TICK. Created by the Patient Information Forum, this quality mark shows we meet PIF’s 10 criteria for trustworthy health information.

Date reviewed

Reviewed: 01 April 2022
Next review: 01 April 2025
Trusted Information Creator - Patient Information Forum
Trusted Information Creator - Patient Information Forum

Our cancer information meets the PIF TICK quality mark.

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