Each person reacts differently to treatment. Whether you experience side effects and if they are mild or severe depends on your treatment and how your body reacts to it. Sometimes changes are temporary and disappear after treatment ends. For some people, changes are longer lasting or even permanent.
Learn more about:
Common oral side effects
Your treatment team will discuss the oral side effects that you may experience and suggest ways to manage them.
Common oral side effects are:
| Mouth changes | You might have mouth sores and ulcers (oral mucositis), thick saliva or a dry mouth (xerostomia). |
| Tooth decay | Your teeth may be at increased risk of decay, especially if you have a dry mouth. |
| Mouth infections | The most common infection is oral thrush, which usually appears as white or red patches, or a white/yellow coating on the mouth and tongue. Thrush can affect your taste, cause bad breath and be uncomfortable. Your treatment team can prescribe medicine to help treat mouth infections. |
| Bleeding gums | Your gums may look red, shiny or swollen and they may bleed. Bleeding may occur if you don’t have enough platelets in your blood, which can happen with chemotherapy. Platelets help the blood to clot. |
| Taste changes | Cancer treatment may make foods taste different (e.g. bland, bitter or metallic). You may lose interest in eating (loss of appetite). |
| Trouble swallowing (dysphagia) | This can be caused by head and neck cancer or treatment side effects. Treatment to the head and neck area can affect swallowing. If you are having difficulty swallowing, you can ask your doctor for a referral to a speech pathologist. |
| Difficulty opening your mouth (trismus) | This can be caused by the cancer or cancer treatments. If opening your mouth is difficult, a speech pathologist may be able to help you. |
Your doctor may refer you to a dietitian or speech pathologist to help you manage your oral side effects and make eating and drinking easier.
For more information about caring for your mouth, see Taste and smell changes and Nutrition and cancer.
Oral mucositis and saliva changes
Oral mucositis
Some treatments – for example, radiation therapy to the head or neck area, some chemotherapy and targeted therapy drugs – can damage the cells lining the mouth. This is known as oral mucositis.
Symptoms include:
- painful spots, sores or ulcers in your mouth
- bleeding in the mouth
- mouth infections such as oral thrush
- discomfort and pain when eating, drinking, speaking or wearing dentures
- sensitivity to certain foods and drinks.
Some medicines help to reduce the discomfort when you eat, drink or speak, and can be applied directly to the mouth sores to numb them. Mucositis usually gets better a few weeks or months after treatment ends.
Dry mouth and saliva changes
Radiation therapy or surgery to the head or neck area, some chemotherapy drugs and some pain medicines can reduce the amount of saliva (spit) in your mouth or make your saliva thick and sticky.
Symptoms include:
- not having as much saliva as usual
- thick or stringy saliva
- a sticky or dry feeling in your mouth
- problems chewing, tasting and swallowing
- difficulty speaking (your tongue may have trouble moving)
- ridges or cracks on the tongue or corners of the mouth
- difficulty with swallowing saliva or spitting it out
- a thick coating on the tongue
- taste changes.
How quickly these symptoms improve is different for every person. Talk to your treatment team about what to expect after treatment.
→ READ MORE: Taking care of your mouth during and after treatment
At times life was tough but it slowly improved. I still suffer from a dry mouth and always carry a bottle of water.
Mary, head and neck cancer survivor
Video: How to eat well after a cancer diagnosis
Podcast: Appetite Loss and Nausea
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Key resource
Download a PDF booklet on this topic.
More resources
Dr Sophie Beaumont, Head of Dental Oncology, Peter MacCallum Cancer Centre, VIC; Dr Teresa Brown, Assistant Director Dietetics, Royal Brisbane & Women’s Hospital, QLD; Ken Colbert, Consumer; Sarah Davies, Head and Neck Nurse Practitioner, Chris O’Brien Lifehouse, NSW; Dr Adrian DeAngelis, Oral and Maxillofacial Surgeon, Royal Melbourne Hospital and OMFS, VIC; Tess Dunlop, Speech Pathologist, Peter MacCallum Cancer Centre, VIC; Elizabeth Egan, Clinical Nurse Consultant – Oncology, St John of God Subiaco Hospital, WA; Alan Harding, Consumer; Dr Michelle Kang, Oral Medicine Specialist, Sydney Oral Medicine, Sydney and Hunter New England Local Health Districts, NSW; Julie McGirr, 13 11 20 Consultant, Cancer Council Victoria; Amy O’Halloran on behalf of Chris O’Brien Lifehouse Dietetics Team, NSW; Megan Sanders, Clinical Dietitian, Head and Neck Services, Peter MacCallum Cancer Centre, VIC.
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