Blood in the urine after pelvic radiotherapy
Pelvic radiotherapy can cause long-term changes to the way the bladder works. It can damage the tissue and blood vessels in the lining of the bladder. They can become weaker and bleed more easily and this can cause blood in your urine.
About blood in the urine (haematuria)
Pelvic radiotherapy can damage the tissue and blood vessels in the lining of the bladder. They can become weaker and bleed more easily. This can cause blood in the urine (haematuria).
If you have blood in the urine, you are likely to need tests to find the cause. There may be other reasons, such as infection. It is important to rule these out first.
You may have a test called a cystoscopy. This uses a thin tube with a camera and light on the end (a cystoscope) to look inside the bladder. During the cystoscopy, the doctor may decide to treat the bleeding by using heat to seal the blood vessels. This is called cauterisation or diathermy. It can be done with an electrical current or laser.
Related pages
Treating blood in the urine
If there is only a small amount of bleeding caused by radiotherapy, you may not need any treatment. But if the bleeding is regular or heavy, or you become anaemic (have a low number of red blood cells), you are likely to need treatment.
Possible treatments include:
Tablets
Tranexamic acid (Cyklokapron®) tablets can reduce bleeding.
Your doctor may prescribe you these tablets for a short time. There is a slightly increased risk of having a blood clot with tranexamic acid. You can discuss this with your doctor before taking the tablets.
Bladder wash-out
If you are passing blood clots in your urine, these may need to be flushed out to make sure they do not block your urethra. A nurse or doctor slowly passes liquid through a tube (catheter) into your bladder. Then the liquid is gently drawn back out using a syringe or drained into a bag. This can be repeated until the clots have gone.
Sometimes a catheter with an extra opening can be used. This means a bag of fluid can be attached to the catheter. The fluid washes clots out of the bladder and drains into a catheter bag. This is called bladder irrigation.
If you are still having blood clots after a bladder wash-out, your healthcare team may try a bladder wash-out during a cystoscopy.
Treating anaemia
Sometimes bleeding from the bladder causes anaemia. This is when you do not have enough red blood cells to carry oxygen around the body.
Anaemia can make you feel breathless or tired. Your doctor may suggest you take iron supplements, which will help you make red blood cells. This will improve your symptoms and make you feel better. Some people may need a blood transfusion.
If bladder problems do not improve
If your bladder symptoms continue or do not improve after having these treatments, your specialist may talk to you about other possibilities. When symptoms are severe, an operation to remove the bladder may be an option, but this is very rare.
We have information about coping with bladder or bowel problems.
Getting support
Macmillan is here to support you. If you would like to talk, you can do the following:
- Call the Macmillan Support Line on 0808 808 00 00.
- Chat to our specialists online.
- Visit our cancer treatment forum to talk with people who have had cancer treatment, share your experience, and ask an expert your questions.
About our information
This information has been written, revised and edited by Macmillan Cancer Support’s Cancer Information Development team. It has been reviewed by expert medical and health professionals and people living with cancer.
-
References
Below is a sample of the sources used in our late effects of pelvic radiotherapy information. If you would like more information about the sources we use, please contact us at informationproductionteam@macmillan.org.uk
C Helissey, S Cavallero, C Brossard et al. Chronic Inflammation and Radiation-Induced Cystitis: Molecular Background and Therapeutic Perspectives. PubMed. 2020 Dec 24;10 Available at https://pubmed.ncbi.nlm.nih.gov/33374374/ [accessed March 2026]
Urinary incontinence and pelvic organ prolapse in women: management. National Institute for Health and Care Excellence. (NICE) guideline Reference number:NG123 Published: 02 April 2019 Last updated: 24 June 2019. Available at https://www.nice.org.uk/guidance/ng123 [accessed March 2026]
LUTS in men. National Institute for Health and Care Excellence. (NICE) Last revised in June 2025. Available at https://cks.nice.org.uk/topics/luts-in-men/ [accessed March 2026]
Date reviewed
This content is currently being reviewed. New information will be coming soon.
Our cancer information meets the PIF TICK quality mark.
This means it is easy to use, up-to-date and based on the latest evidence. Learn more about how we produce our information.
The language we use
We want everyone affected by cancer to feel our information is written for them.
We want our information to be as clear as possible. To do this, we try to:
- use plain English
- explain medical words
- use short sentences
- use illustrations to explain text
- structure the information clearly
- make sure important points are clear.
We use gender-inclusive language and talk to our readers as ‘you’ so that everyone feels included. Where clinically necessary we use the terms ‘men’ and ‘women’ or ‘male’ and ‘female’. For example, we do so when talking about parts of the body or mentioning statistics or research about who is affected.
You can read more about how we produce our information here.