Radiation therapy impacts each individual differently. This means that the side effects can vary from person to person.

Radiotherapy is one of the most important treatment options for cancer. With improved technology targeting and eliminating cancer cells using radiation therapy has proven to be most effective in the treatment of cancer. Depending upon the part of the body affected and the extent of the spread of cancer, the intensity and frequency of radiotherapy is adjusted. In some cases, radiotherapy is the only mode of treatment, in others, it is carried out along with chemotherapy and/or surgery.


Radiotherapy uses high-energy particles such as x-rays, gamma rays or electron beams to destroy cancer cells. It breaks the very DNA of the cells, preventing it from growing and multiplying – therefore causing the cells to die. However, even the most precise radiotherapy machines, tend to damage a few of the healthy cells in the vicinity of the cancerous ones. Nevertheless, unlike chemotherapy and oral cancer medication that travels through the whole of the body, radiotherapy hits only the affected region – minimizing the body’s exposure to harsh chemicals.





Besides the most obvious reason, which is to destroy cancer cells, Radiotherapy has other goals too.


  • Radiotherapy is used to shrink tumours, which are then surgically removed.
  • Once the tumour has been removed, radiotherapy can be used to treat areas where the cancer spreads most to destroy cancer cells before they grow into tumours.
  • Radiotherapy is also used in palliative care when the cancer has spread too much. In such cases, radiotherapy helps ease symptoms of advanced cancer.
  • In case the cancer returns, depending on how much radiation was previously administered, the patient may undergo radiotherapy again.



As with the case of any medical treatment, radiation therapy impacts each individual differently. This means that the side effects can vary from person to person. Similarly, some side effects will go away as soon as the treatment ends, while some last much longer, and a few side effects may show up months after treatment has ended. Before starting radiotherapy, it is best to discuss the different types of side effects and prepare oneself for them.


Some general side effects are listed below.




This is by far the most common side-effect of radiation therapy irrespective of what part of the body is targeted. It may not occur soon after the first session, but after a few weeks of radiotherapy, one might start feeling tired. The main cause being radiotherapy destroys some healthy cells as well – it is inevitable. As treatment progresses, fatigue may increase. You need to keep track of how bad it is getting and perhaps take a few days off from work to rest.




The skin that comes in contact with radiotherapy may turn red or blistered or appear swollen. Some patients feel like their skin has been sunburnt. Repeated exposure of the same areas to radiation can cause the skin to be itchy and flaky, leading to a condition called radiation dermatitis. The condition subsides once treatment stops. In the meantime, for as long as you are undergoing radiotherapy you need to protect affected regions of the skin better.


  • Wear loose, soft clothing to minimise friction.
  • Use a gentle cleanser or a mild soap while washing, and do not scrub/ scratch the area.
  • If you can avoid shaving or any hair removal attempts on that region, which would be the best. Else consult with your cancer care team on what to do.
  • Never step outdoors without sunscreen. Ask your cancer care doctor to prescribe one that will protect you without irritating your skin further.



The area of the skin exposed to radiation tends to shed hair. If you receive radiation therapy on your head or neck, there is a possibility that you will lose hair. Know that your hair will grow back once the treatment ends. The skin on your scalp may now be tender and it’s best to keep it covered using a soft scarf or a hat. If you wish to use a wig, discuss the same with your cancer care team first.




Many people state that during radiotherapy they do not have much of an appetite or are unable to eat even. For some, the regular food that they eat does not taste the same any more. However, as your body attempts to recover from radiation therapy it is important for you to eat healthily.


  • If you have no appetite or are having difficulty chewing/ swallowing, eat smaller meals throughout the day instead of three large ones.
  • Eat slowly but eat meals that have enough proteins and minerals.
  • Before taking supplements consult with your doctor.
  • At those times when you are feeling energetic, grab a few extra bites.
  • Drink plenty of fluids and stay hydrated.



This is most often a side-effect experienced by those receiving radiation to the stomach, intestines or colon. However, nausea and vomiting is experienced by other patients as well. This could be due to appetite changes as well. The best way to combat nausea is by eating small, light, bland meals. Talk to your cancer care team if the nausea is too much and you are unable to function normally.


Depending on the region targeted by radiation therapy, side effects may vary. For instance, those undergoing radiotherapy in the pelvic region must talk to their doctor about possible fertility issues or the impact on one’s sexual life. Those undergoing radiotherapy to the head and neck are likely to experience headaches, dry mouth, trouble swallowing, and even blurring of vision. Whatever the side effects are, make it known to your cancer care team. They will be able to advise you on how to deal with the side effects and still go ahead with treatment.


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