Radiation therapy side effects

During cancer treatment, you may experience different side effects. These can vary depending on the type of cancer you have, the stage of your cancer and the kind of treatment you are undergoing.

Radiation therapy treatment can affect your body in different ways. It’s important to understand these effects and how you can keep your body healthy throughout treatment.

As radiation is targeted to a specific area of the body, you generally will only experience side effects in the area being treated. Your radiation oncologist and treatment team will discuss the type of side effects you may experience before your treatment begins.

Although most side effects are temporary and resolve after your radiation therapy has finished, there is a possibility that long-term effects may occur. Please discuss with your radiation oncologist as he/she is the best person to provide more details and this will be covered in the consent process before you start your treatment.

Skin reaction

During treatment your skin may become red, itchy or irritated. Towards the end of treatment, the skin reaction can become more intense however usually returns to normal four to six weeks after treatment finishes.


Another common side effect you may have during your treatment is fatigue, a feeling of exhaustion and lack of energy. You may feel tired or lack energy for daily activities during your treatment. This is a common reaction to radiation therapy and each person can be affected differently. Finding a balance between rest and activity will help you manage daily life.

Nausea and vomiting

Nausea and vomiting can be common reactions from radiation therapy to certain areas of the body, such as the abdomen.

Bowel irritation

Radiation therapy can irritate the lower part of the bowel and you may experience some related symptoms towards the end of your treatment. Symptoms of irritation can include:

  • An increase in the amount of bowel motions
  • Softer/looser bowel motions
  • Discomfort in passing a bowel motion
  • Urge to use your bowels without passing a motion (tenesmus)
  • Bleeding from the rectum (especially if you have haemorrhoids)
  • Mucus discharge

Bladder irritation

As you progress through your treatment, radiation therapy can irritate the bladder lining and the urethra (the tube that you urinate through).

Symptoms can include:

  • The need to urinate more often, including overnight
  • A sudden urge to empty your bladder
  • A burning sensation when you urinate
  • Change or reduction in your urine flow/stream and/or difficulty urinating
  • Blood in the urine

Sexual function

The effect of radiation therapy to sexual function can be different for everyone and will depend on the area being treated.

You can continue sexual activity without causing harm to your partner. However, it is important to use contraception to avoid pregnancy during treatment.

Radiation therapy to the prostate can affect the nerves that control erections and this may affect your ability to maintain an erection or you may feel a burning sensation during ejaculation. Your desire to have a sexual relationship may also decrease during treatment.

Pain and discomfort

Radiation therapy can cause a temporary increase in pain, swelling and aches in the area being treated.

Hair loss

Radiation therapy to the skin may cause the hair in the treatment area to fall out, usually a few weeks after treatment begins. Hair will usually regrow within three to six months. The colour or texture may be different, and it may grow back thinner or patchy.

Occasionally, hair loss can be permanent if you have a high dose of radiation therapy. Your doctor will discuss this with you before you start your treatment.

Difficulty swallowing

Difficulty swallowing is a common reaction when the throat or oesophagus is in the treatment area. The throat may become inflamed and feel painful when swallowing or produce a sensation like a lump in the throat.

Changes in the mouth

Radiation therapy to the head and neck may cause changes in the mouth such as a temporary change or loss of taste, dry mouth, oral thrush and mouth ulcers.


It is possible to develop a cough as a side effect of radiation therapy to the chest. A cough suppressant or other medication may be prescribed to help manage a cough.

Shortness of breath

Radiation therapy to the chest area may cause some inflammation of your lungs. This inflammation may cause you to become short of breath. It is important to report any breathing changes to your treatment team.


Whether fertility is impacted by radiation therapy depends on the area that is receiving treatment. If you are a woman having radiation therapy to the abdomen or pelvis, the amount of radiation absorbed by the ovaries will determine the potential impact on your fertility. Radiation to the pituitary gland may also affect your fertility, as this gland normally signals the ovaries to ovulate.

Radiation to both testes in men is rare. However, if this is part of your treatment plan your fertility will be affected. If the radiation fields include the pelvis, for example in the treatment of rectal, prostate or soft tissue sarcoma at the buttock or upper leg areas, there may be scattered radiation doses to the testes that can affect your fertility and this can be temporary or permanent depending on the radiation doses received.

Please speak with your radiation oncologist if you or your partner wish to become pregnant or you have fertility concerns.

Understanding fees

We will work with you to ensure you’re aware of any out-of-pocket expenses and make sure there are no surprises throughout your treatment.
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Care team

Every member of our team are here to help you. Here are some of the people you may meet and the role they have in your care.
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  • 04 896 0200
  • Level B3, Bowen Specialist Medical Centre 98 Churchill Drive Crofton Downs Wellington 6035