While radiotherapy can destroy cancer cells, it can also affect some of the normal cells in the treatment area. Radiotherapy affects people in different ways, so it is difficult to predict exactly how your treatment will affect you.

For many people, most of the side effects will be temporary (short term) and will disappear over a few weeks or months once the treatment has ended. The short-term side effects are discussed in the next section.

For some women, one or two of the side effects mentioned here may never go away after treatment and may become long-term problems.

Sometimes, side effects which start during radiotherapy get better after the treatment finishes but then problems may start to occur many months or even years later.

It is very important to let your cancer specialist know if the side effects of your radiotherapy have not got better a few weeks after the treatment has ended. It is also important to let your doctor know if you get new side effects or if any side effects get worse after the treatment. There may be a lot of things that can help you. This information aims to help you to manage any side effects that occur, to allow you to live life as fully as possible.

It can be very frightening if you start to get side effects or if they get worse some time after treatment – as you may worry that the cancer has come back. Some of the long-term effects of radiotherapy give symptoms which are the same as the cancer coming back.

The risk of the cancer coming back varies according to the type and stage of cancer and the dose of treatment that was given, so it is not possible to give that information in this section. Your cancer specialist is familiar with all your medical details and is the best person to talk to. They can discuss whether your problems are due to the effects of the radiotherapy treatment or whether the cancer could have come back. Where we can, we have included a rough guide about how common each radiotherapy side effect is. This is to give you an idea of whether a symptom is likely to be due to the treatment or to the cancer.

If necessary, your specialist can arrange for you to have tests to check whether your symptoms are due to the treatment or to a recurrence of the cancer.

• A continuing pain that doesn't go away with your usual painkillers
• Lumps, bumps or swellings
• Diarrhoea, constipation or loss of appetite
• Unexplained weight loss or weight gain
• Bleeding from the bladder (in the urine) or back passage
• Bleeding or discharge from the vagina
• Any other unusual problems that continue for more than a couple of weeks

You can contact:

• Your cancer doctor
• Your specialist nurse
• Your hospital clinic to make an earlier appointment
• Your GP (who can refer you to a specialist if necessary)

Throughout this section, people who can help with specific problems are mentioned wherever relevant.