Difficulty swallowing

Radiotherapy to the chest might cause swelling and soreness in the throat and food pipe (oesophagus) and you might have difficulty swallowing (dysphagia). This side effect usually starts with a feeling of a lump in the throat.

Swallowing problems

Whether you have problems swallowing depends on where exactly you are having treatment and if your throat or oesophagus is in the radiotherapy treatment area. It also depends on the amount (or dose) of radiation given. Difficulty swallowing may be worse and can last longer if you have chemotherapy at the same time as radiotherapy.

If you are having radiotherapy to your oesophagus this area will be targeted directly with treatment and the lining of the oesophagus will become irritated during the treatment. Let your health care team know as soon as swallowing becomes uncomfortable. They can prescribe soothing medication to help. 

There is a very small risk of damage to the oesophagus which can cause an ulcer or hole to develop, that may need surgery. 

Occasionally, if you cannot swallow at all, a temporary feeding tube will need to be inserted. Sometimes this is a fine tube down the throat (a nasogastric or ‘NG’ tube), or sometimes through the skin of the abdomen into the stomach (a PEG or a RIG tube).  

As with all radiotherapy side effects, they tend to build up over time. This means you might experience problems after about a week and then this can continue for around 2 weeks after radiotherapy.

In some hospitals, you'll see a dietician weekly during treatment. If not you can ask to see a dietitian if you're having problems.

Food and drink tips

You might find you'll need to make changes to the food and drink you usually eat. A soft, plain diet is usually best. 


Try different foods to find out which are easiest to swallow. This includes:

  • porridge
  • soup or broth
  • milk
  • cool drinks and ice cream

Avoid eating things that may irritate your throat or oesophagus. Such as:

  • dry foods
  • spicy foods
  • very hot foods or drinks
  • alcohol, particularly spirits

You could try grazing or snacking and eating little amounts often, rather than sitting down to bigger meals at regular meal times.

You can try adding calories to your diet (calorie loading), so add cream in your coffee, swop to full fat milk or add cheese and butter to mashed potatoes. This way you are increasing your calorie intake without having to eat lots of food. 


High calorie drinks can also boost your calorie intake, such as:

  • Build Up
  • Complan
  • Fortisip/Fortijuice
  • Ensure

Other high calorie food supplements are available on prescription. You can ask your specialist nurse, radiographer or dietitian to advise you.

Remember to drink plenty of other fluids too.

Medicines that can help

Your doctor or nurse can prescribe medicines to reduce the soreness, including:

  • painkillers
  • liquid medicines

You could take painkillers about half an hour before meals to make eating less uncomfortable.

  • Devita, Hellman and Rosenberg's Cancer Principles and Practice of Oncology (11th edition)
    VT Devita, TS Lawrence and SA Rosenberg
    Wolters Kluwer Health, 2019

  • Practical Radiotherapy Planning
    A Barrett and others, 
    Hodder Arnold, 2009

Last reviewed: 
10 Nov 2020
Next review due: 
10 Nov 2023

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