Radiotherapy side effects
Radiotherapy uses radiation to treat cancer. It aims to give a high dose of radiation to the cancer but as low a dose as possible to the surrounding healthy cells. This gives the highest chance of curing or shrinking the cancer, while reducing the risk of side effects.
While radiation kills the cancer cells, the normal cells are usually able to recover. And your side effects generally get better over a few weeks.
It's difficult to predict exactly what side effects you will have and how bad they might be. Before you start treatment, your doctor will explain any possible side effects of the treatment. They will also discuss the best way to manage them. Knowing about the side effects can help you to prepare for them. Usually the side effects improve a few weeks after treatment. But some might continue long term.
Ask your doctor about any possible long term side effects that the treatment may cause or anything else you might be worried about.
This video shows people affected by cancer talking about the general side effects of radiotherapy. The video is around 7 and a half minutes long.
Radiotherapy affects people in different ways. It's difficult to predict exactly what side effects you will have and how bad they might be. Some people only have mild side effects but for others the side effects can be more severe.
Radiotherapy can affect your bone marrow and blood cells. This is more likely if you're having treatment to a large area of your body.
You should try to eat a healthy and balanced diet during radiotherapy. You may have problems eating if you have radiotherapy to your head or neck.
External radiotherapy can cause hair loss in the area where you are having treatment. Your hair may come back after treatment finishes or the hair loss can be permanent. Find out how to take care of your hair during treatment.
You might feel many different emotions during radiotherapy. Being tired can make any of the emotions that you're feeling even worse. There are ways to get help and support.
Radiotherapy treatment can affect your skin making it sore and look redder or darker than usual. Find out about ways to help your skin.
You might feel tired during your radiotherapy treatment and for a few weeks afterwards. Read about why this is and things you can do to help.
You have different side effects depending on which area of the body is being treated. Tell your radiotherapy team about any side effects you have.
They can help you find ways of reducing the effects and coping with them.
Find out about radiotherapy side effects for different parts of the body
For many people, the side effects of radiotherapy wear off within a few weeks of the treatment ending. But for some people radiotherapy can cause long term side effects.
The possibility of long term side effects depends on the type of cancer, its size and position. It might also depend on how close the cancer is to nerves or other important organs or tissues.
It is important to ask your doctor about the possibility of long term side effects. Depending on the position of the cancer the possible long term effects might include:
a change in skin colour in the treatment area
red spidery marks on your skin (telangiectasia) caused by broken blood vessels
a dry mouth
breathing problems
loss of ability to become pregnant or father a child (infertility)
low sex drive
erection problems (impotence)
soreness and pain
bowel changes
bladder inflammation
drainage channels to the arms or legs can become partly blocked resulting in swelling called lymphoedema
Read more about the long side effects of radiotherapy
You may feel anxious about radiotherapy side effects and this is normal. It can help to talk through any worries you have with your doctor, nurse or radiographer.
Last reviewed: 11 Jan 2024
Next review due: 11 Jan 2027
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