Following radiotherapy, it is highly likely that you will have some side effects. Side effects occur because radiotherapy temporarily damages some of the healthy cells as well as destroying the cancerous ones.
Side effects will depend on:
- the part of your body being treated
- the dose of radiotherapy
- how quickly the healthy cells are able to repair the damage
Radiotherapy affects different people in different ways and it is difficult to know exactly how you will react to the treatment.
Some people experience mild side effects following radiotherapy, while others experience more severe effects. Some side effects begin during treatment whereas others can appear weeks or months afterwards.
Before starting treatment, you should discuss the possible side effects with your treatment team.
Common side effects of radiotherapy include:
- sore skin
- tiredness
- feeling sick
- dry mouth
- loss of appetite
- diarrhoea
- hair loss
- discomfort on swallowing
- a lack of interest in sex
- stiff joints and muscles
These are explained in more detail below.
Sore skin
Your skin may become red and sore in the area being treated towards the end of a course of radiotherapy, or for a couple of weeks afterwards.
Depending on the area being treated, and the individual’s reaction to radiation, some people’s skin may peel after having a course of radiotherapy. This usually heals within a couple of weeks.
Your treatment team will be able to give you advice about the best way of caring for your skin during treatment. If your skin becomes sore, you should try not to irritate it further.
You should avoid shaving and using perfumed soap in the affected area. Protect your skin from cold winds and wear a high-factor sunscreen (SPF 15 or above) to protect your skin from the sun.
Tiredness
You will probably feel tired both during and after having radiotherapy. Doing some gentle exercise may help to relieve the symptoms of tiredness.
Tiredness is particularly common towards the end of a course of radiotherapy and it can last for some time afterwards. It usually occurs as a result of the body repairing the damage to healthy cells.
A shortage of red blood cells (anaemia) can also contribute to tiredness during radiotherapy.
For some cancers, regular blood tests may be required during radiotherapy to ensure that you are not becoming anaemic. If you have anaemia, you may need to have a blood transfusion (where you receive blood that is removed from another person who is known as a donor).
Feeling sick (nausea)
Most people are not sick during radiotherapy. However, some people feel sick (are nauseated) at the start of, during, or for a short time after, their treatment. If you experience nausea, your doctor may be able to prescribe medication to help control it.
Radiotherapy to your abdomen (tummy area) or pelvic area may make you sick. This can last a few days after your treatment stops. Again, medication or complementary therapies can help.
Your oncologist may also recommend that you take some anti-sickness medication during your treatment to prevent sickness.
Loss of appetite
The combination of feeling sick and tired during radiotherapy can make you lose your appetite. You may have difficulty swallowing if you are having radiotherapy to your head, neck or chest.
If you have difficulty eating, you may find it easier to eat several small meals throughout the day, rather than a few larger meals. You can also speak to your radiotherapist who may refer you to a dietitian (nutritional specialist).
Diarrhoea
Diarrhoea is a common side effect of radiotherapy to the abdomen or pelvic area. It usually starts a few days after treatment begins and gradually gets worse as treatment continues. You should tell your doctor if you notice any blood in your stools (faeces).
After your treatment has finished, diarrhoea should disappear within a few weeks. You should tell your doctor if your symptoms have not improved after a few weeks.
Hair loss
Hair loss is a common side effect of radiotherapy to your head or neck. Radiotherapy will only cause hair loss in the area being treated.
Many people find losing their hair stressful and difficult to cope with. Losing your hair can affect your self-confidence and it may make you feel depressed.
Talk to your family and friends about how you are feeling so that they can support you. After a few weeks of finishing treatment, your hair should start to grow back. Read more about cancer and hair loss.
You may consider getting a synthetic (man-made) wig or a wig that is made from human hair. Synthetic wigs are available free on the NHS for certain people including:
- inpatients (those who need to stay in hospital overnight for treatment)
- those under 16 years of age
- those between 16 and 19 years of age who are in full-time education
Read more about wigs, including the details of other groups who are eligible for getting wigs free on the NHS and how to get help with health costs.
Discomfort on swallowing
Radiotherapy to the chest can cause the tube through which food passes (the oesophagus) to become temporarily inflamed, which may cause temporary discomfort when swallowing. If required, your doctor will be able to prescribe medication to help soothe your throat.
Effects on sex and fertility in women
Having radiotherapy may cause you to lose interest in sex, particularly if you have other side effects, such as tiredness or nausea, or if you are anxious about your condition or treatment.
You should avoid eating hot or spicy food and drinking acidic drinks or spirits during this time because they can aggravate the problem.
Radiotherapy to the vaginal area may cause your vagina to become sore and narrower. Your radiotherapist will tell you how you can treat this using a vaginal dilator, which is a device that is inserted into your vagina to help prevent it narrowing. Having sex regularly after your treatment can also help prevent your vagina narrowing.
If you experience vaginal dryness or pain when having sex, you can use lubricants or ask your GP or radiotherapist to prescribe appropriate medication. Radiotherapy to other areas of the body will not affect your ovaries or make you infertile.
Read more about the effects on female sex and fertility on the Cancer Research UK website.
Effects on sex and fertility in men
In men, temporary erectile dysfunction (the inability to get and maintain an erection) and loss of interest in sex are common side effects of pelvic radiotherapy. Read more about erectile dysfunction.
Radiotherapy to other areas of your body will not make you infertile or cause any problems if you decide to have children in the future.
If there is a risk that you could become infertile following radiotherapy, your doctor will discuss this with you before your treatment. It may be possible to store your sperm until you decide to have a baby, although this is not always available on the NHS.
Read more about the effects on male sex and fertility on the Cancer Research UK website.
Stiff joints and muscles
Radiotherapy can sometimes cause your muscles to tighten up and your joints to become stiff in the area being treated. You may also experience some uncomfortable swelling in the affected area.
Exercising your joints and muscles regularly can help prevent stiffness. If you have stiff joints and muscles, your doctor or radiotherapist may refer you to a physiotherapist, who will be able to recommend suitable exercises for you.
Read more about physiotherapy.
