- Home
- Head and neck cancers
- Treatment
- Radiation Therapy
- Side effects of radiation therapy
Side effects of radiation therapy
The side effects vary depending on the area treated, the number of treatments, the type of radiation therapy you have and whether it is combined with chemotherapy.
Side effects often peak in the final week of treatment, or shortly afterwards, then start to ease 2–3 weeks after treatment ends. Some side effects may last longer, be ongoing or appear several months or years later. Learn more about managing side effects. The most common short-term and long-term side effects are listed below.
During or immediately after treatment – fatigue, mouth sores, taste changes, loss of appetite, dry mouth and thick saliva, skin redness and burning in the area treated, breathing difficulties, weight loss.
Ongoing or permanent – dry mouth, thick saliva, difficulties with swallowing and speech, changes in taste, fatigue, muscle stiffness, neck swelling, appetite and weight loss, oral thrush, hoarseness, dental problems, difficulty opening the mouth, hair loss.
Some people find that food and fluid goes into the windpipe instead of the food pipe. This is called aspiration and it can block the airways and cause difficulty breathing. Some people develop an underactive thyroid (hypothyroidism) and may need to take thyroid hormone replacement tablets after radiation therapy.
For more on this, see Radiation therapy.
Listen to our podcasts on Making Treatment Decisions and Coping with a Cancer Diagnosis
Additional resources
A/Prof David Wiesenfeld, Oral and Maxillofacial Surgeon, Director, Head and Neck Tumour Stream, The Victorian Comprehensive Cancer Centre at Melbourne Health, VIC; Alan Bradbury, Consumer; Dr Ben Britton, Senior Clinical and Health Psychologist, John Hunter Hospital, NSW; Dr Madhavi Chilkuri, Radiation Oncologist, Townsville Cancer Centre, The Townsville Hospital, QLD; Jedda Clune, Senior Dietitian (Head and Neck Cancer), Sir Charles Gairdner Hospital, WA; Dr Fiona Day, Staff Specialist, Medical Oncology, Calvary Mater Newcastle, and Conjoint Senior Lecturer, The University of Newcastle, NSW; Dr Ben Dixon, ENT, Head and Neck Surgeon, Peter MacCallum Cancer Centre and St Vincent’s Hospital Melbourne, VIC; Emma Hair, Senior Social Worker, St George Hospital, NSW; Rosemerry Hodgkin, 13 11 20 Consultant, Cancer Council WA; Kara Hutchinson, Head and Neck Cancer Nurse Coordinator, St Vincent’s Hospital Melbourne, VIC; A/Prof Julia Maclean, Speech Pathologist, St George Hospital, NSW; Prof Jane Ussher, Chair, Women’s Health Psychology, Translational Health Research Institute (THRI), School of Medicine, Western Sydney University, NSW; Andrea Wong, Physiotherapist, St Vincent’s Hospital Melbourne, VIC. We also thank the health professionals, consumers and editorial teams who have worked on previous editions of this title.
View the Cancer Council NSW editorial policy.
View all publications or call 13 11 20 for free printed copies.
Need to talk?
Support services
Coping with cancer?
Speak to a qualified health professional someone who has been there, support groups & forum
Need legal and financial assistance?
Practical advice and support during and after treatment
Work and cancer
Information for employees, employers and workplaces dealing with cancer
Cancer information
Making cancer treatment decisions
Decision-making steps, consent and second opinions
What is radiation therapy?
Key questions about radiation therapy as part of cancer treatment
View our publications
Guides and fact sheets for people with cancer, their families and friends