“Does radiotherapy hurt?” is one of the most common questions people ask before starting cancer treatment.
With external beam radiotherapy, the radiation itself causes no pain as it passes through the body. You lie on the treatment table and the radiotherapy machine moves around you without touching your body, and you cannot feel the radiation.
During treatment, however, radiotherapy can affect healthy cells near the area being treated and cause some side effects. Not everyone experiences the same ones, and the part of the body being treated has a great deal to do with which side effects appear.
7 common side effects of radiotherapy and how to care for them
1. Fatigue
This is one of the most common side effects.
You may feel:
- Short of energy
- More easily tired by everyday tasks
- In need of more rest
- Unable to keep up your usual routine
Fatigue can build up during radiotherapy and continue for several weeks or months after treatment ends.
What can you do?
- Rest when your body needs it
- Give priority to the things that matter most
- Keep up light activity such as walking if your health allows
- Eat enough energy and protein
- Ask family for help when you need it
Do not push yourself to carry on “as normal” if your body needs more time to recover.
2. Red, dry or itchy skin in the treated area
The skin in the treated area may become:
- Dry
- Itchy
- Red or changed in colour
- More sensitive
- Flaky or peeling in more severe cases
These changes are usually confined to the area being treated.
How to care for it:
- Wash the treated skin gently
- Pat it dry rather than rubbing
- Wear loose, soft clothing
- Avoid compresses that are too hot or too cold
- Protect the skin from the sun
- Only use creams or skincare products as directed by your radiotherapy team
If the skin blisters, weeps, becomes very painful or shows signs of infection, tell a healthcare professional straight away.
3. Loss of hair in the irradiated area
If the radiation passes through an area that has hair, that hair may fall out.
For example:
Radiotherapy to the brain → hair may fall out on the part of the head being treated.
Radiotherapy to the pelvis → hair may fall out in the treated area.
How much hair grows back after radiotherapy depends on the dose and the area treated.
How to care for it:
- Wash and care for your hair gently
- Avoid pulling or rubbing hard
- Protect your scalp if it is sensitive
- Ask your doctor whether your hair is likely to grow back with your particular regimen
4. Nausea or vomiting
Not every site of radiotherapy causes nausea.
It is more common with radiotherapy to the upper abdomen, the brain or the whole body.
What can you do?
- Eat small meals
- Choose foods that are easy to eat and have little smell if you are sensitive to odours
- Drink as much fluid as you can manage
- Tell your doctor if nausea is affecting how you eat and drink
Anti-sickness medicines can be used to prevent or ease the symptoms.
5. Mouth pain, dry mouth or difficulty swallowing
This side effect is usually linked to radiotherapy to the head, neck or chest, and not everyone having radiotherapy will experience it.
Patients may experience:
- A dry mouth
- Mouth pain or ulcers
- Changes in taste
- Pain when swallowing
- More difficulty eating and drinking
How to care for it:
- Keep up gentle oral hygiene
- Choose soft foods that are easy to swallow
- Avoid food that is very spicy or salty, or that causes irritation
- Sip water regularly if you are allowed to
- Tell your doctor if you are eating and drinking noticeably less
If your eating and drinking is affected, your doctor or a dietitian can help adjust your diet to avoid weight loss and poor nutrition.
6. Diarrhoea or digestive upset
Radiotherapy to the abdomen, rectum or pelvis can affect the digestive tract and cause diarrhoea.
How to care for it:
- Drink enough fluids unless your doctor has told you to restrict them
- Eat smaller meals more often
- Keep track of how often you open your bowels
- Talk to your treatment team before taking any anti-diarrhoeal medicine yourself
Severe diarrhoea can leave the body short of fluids and electrolytes, which in turn makes fatigue worse.
7. Changes in passing urine or in the bladder
Radiotherapy to the pelvis can cause symptoms such as:
- Passing urine more often
- A sudden urge to pass urine
- Discomfort when passing urine
- Other changes in the bladder
These problems depend on the area being treated and do not happen to everyone.
How to care for it:
- Keep track of any changes when you pass urine
- Drink fluids as directed by your doctor
- Tell a healthcare professional if you have severe pain, blood in your urine or symptoms that are getting worse
Do not simply put up with it, as many side effects can be controlled far better when they are dealt with early.
Do side effects go away after radiotherapy?
Most acute side effects improve once treatment has finished, because healthy cells are given time to recover.
The speed of recovery, however, differs from person to person.
Some side effects can last a long time or appear late, after many months or even years. This risk depends on the area treated, the radiation dose, other cancer treatments and many personal factors.
That is why follow-up appointments after radiotherapy remain very important, even when you feel better.
When should you tell your doctor?
Contact your treatment team if you:
- Become suddenly exhausted or short of breath
- Cannot eat or drink
- Are vomiting a lot
- Have severe diarrhoea or signs of dehydration
- Have skin in the treated area that blisters, weeps or is very painful
- Have mouth pain or difficulty swallowing that stops you eating
- Develop any new symptom that worries you
Do not wait until side effects become serious before telling your doctor.
Many symptoms can be prevented or controlled far better when they are picked up early.
5 principles of self-care during radiotherapy
You do not need a special “detox” after each radiotherapy session.
Instead, focus on:
- Eating enough: especially energy and protein, so that your body can recover.
- Drinking enough: unless your doctor has told you to limit fluids.
- Sensible sleep and rest: while still keeping up light activity if your health allows.
- Caring for the treated skin correctly: avoid applying products that have not been recommended.
- Reporting side effects early: rather than trying to put up with them.
The body needs energy and nutrients while it repairs the tissues affected by treatment.
Keeping track of your treatment on Halza
Radiotherapy is usually one part of a cancer treatment journey that involves many appointments, tests and follow-ups.
With Halza, you can store your health records and results so that it is easy to look back over the information at each stage of treatment.
External beam radiotherapy is usually painless while the radiation is being delivered. What matters more is recognising side effects early and caring for yourself properly, so that your body is in a better position to recover throughout treatment.
The information in this article is for reference only and does not replace the advice or treatment instructions of your oncologist and radiation oncologist. Side effects and their care need to be tailored to each person's treatment area and regimen.
Frequently asked questions
Does radiotherapy hurt while the radiation is being delivered?
Usually not.
External beam radiotherapy is much like having an X-ray: you need to lie still in the right position for a few minutes, but you cannot feel the radiation.
What tends to cause discomfort is the side effects that build up over several treatment sessions, not any sensation of radiation entering the body.
Do side effects appear from the very first session?
Not necessarily.
Many side effects appear gradually during treatment. Skin changes, for example, usually start after about 1–2 weeks of radiotherapy. Some side effects ease off once treatment has finished, while some late effects may appear months or even years later.
Does radiotherapy make all your hair fall out?
No.
Radiotherapy usually only causes hair loss in the part of the body that receives the radiation. For example, radiotherapy to the head may cause hair loss in the treated area, but radiotherapy to the chest does not make all the hair on your head fall out.
References
- National Cancer Institute – Radiation Therapy Side Effects
- National Cancer Institute – Radiation Therapy for Cancer
- American Cancer Society – External Beam Radiation Therapy
- NHS – Side Effects of Radiotherapy
- National Cancer Institute – Nutrition During Cancer Treatment
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