Side effects of radiotherapy for invasive and advanced bladder cancer

You may have some side effects during or after radiotherapy. These might include:

  • Diarrhoea and sore skin around the back passage – you may be advised to cut down on the amount of fibre you eat. It’s important to drink lots of fluids.
  • Passing urine more often and having a burning sensation – try to drink plenty of fluids but avoid caffeine, fizzy drinks and alcohol.
  • Dry or sore skin – your radiographer will explain how to look after your skin.
  • Tiredness – try to get plenty of rest and some gentle exercise.

Let your doctor, nurse or radiographer know about any side effects you have as they can often do something to help. Side effects usually gradually disappear after treatment finishes.

Some people have effects that appear after radiotherapy finishes. These are called late effects and can include changes to the vagina, infertility, bowel changes and problems having an erection.

Your doctor or nurse can explain more about any side effects you may have.

Side effects of radiotherapy

Your doctor, nurse or radiographer will discuss side effects with you so you know what to expect. Let them know about any side effects you have during or after treatment, as there are often things that can be done to help. Side effects usually disappear gradually over a few weeks or months after treatment finishes.

There’s more information about side effects in our information about pelvic radiotherapy.

Bowel symptoms

You may have diarrhoea and sore skin around the back passage. Your specialist will prescribe anti-diarrhoea tablets to reduce it. Some people may be advised to cut down on fibre in their diet. It’s important to drink at least two litres (three and a half pints) of fluids a day.

Bladder symptoms

You may need to pass urine more often and have a burning feeling when you pass urine. Your doctor can prescribe medicines to reduce these symptoms.

Drinking plenty of fluids will also help. Try to drink about two litres (three and a half pints) a day. Some fluids can irritate the bladder and make symptoms worse. These include drinks with caffeine, such as tea, green tea and coffee, alcohol, fizzy drinks and drinks containing artificial sweeteners.

These effects usually disappear gradually a few weeks after the treatment has ended.

Effects on the skin

Your skin in the treatment area may redden or get darker and become dry or sore. The radiographer will give you advice on looking after your skin.

Tiredness (fatigue)

Radiotherapy makes you tired and this may continue for several months after treatment. During treatment, you’ll need to get plenty of rest. Try to balance this with some gentle exercise, such as short walks, which will give you more energy. You can gradually build up the amount you do after treatment.

We have more information and a video about coping with fatigue.

Hair loss

You may lose some of your pubic hair. The hair will usually grow back, but may be thinner than it was.

After treatment finished, the tiredness kicked in. A wave came over me and drained all my energy. I had to curl up on the couch until it passed.


Possible long-term side effects

Some effects of radiotherapy can appear after your treatment ends. These are called late effects and there are things you can do that help reduce the risk.

We have more information about the late effects of pelvic radiotherapy.

Effects on the vagina

Radiotherapy to the pelvis can make the vagina narrower, which can make sex difficult or uncomfortable. You may be advised to use a vaginal dilator to try to help prevent this happening. Your specialist nurse or radiographer will give you more advice and explain how to use them. Hormone creams applied to the vagina can also help. These can be prescribed by your doctor.

Effects on erections

For men, radiotherapy to the pelvis can make it more difficult to have an erection. There are treatments that can help with this.


Radiotherapy to the pelvic area is likely to cause infertility in men and women. If you are worried about your fertility, talk to your doctor before your treatment starts.

There is more information about some of these side effects, in our sections about sexuality for men and sexuality for women. We also have information about fertility for men and fertility for women.

Effects on the bowel or bladder

Occasionally, the bowel or bladder may be permanently affected by the radiotherapy. Certain side effects may not improve or side effects may develop years after radiotherapy treatment.

If your bowel is affected, you may have bowel motions more often and have diarrhoea. If your bladder is affected, it may shrink. This means it can’t hold as much and you need to pass urine more often.

The blood vessels in the bowel and bladder can become more fragile. If this happens, blood appears in urine or bowel motions. If you notice blood in your urine or bowel motions, tell your doctor straight away so that tests can be done and the right treatment given.

If you have bladder or bowel problems, you can get a card to show to staff in shops, pubs and other places. The card allows you to use their toilets without them asking awkward and embarrassing questions. You can the card from the Bladder and Bowel Community. Macmillan also produces a toilet card, which you can order from be.mac.

The National Key Scheme (NKS) offers access to about 9,000 locked public toilets across the UK. You can buy a key from Disability Rights UK. They can also send you details of where the toilets are located.

Back to Radiotherapy explained

Who might I meet?

You will meet many different specialists before, during and after radiotherapy treatment.