Side effects during treatment

How pelvic radiotherapy affects you will depend on the type of cancer you have, the dose of radiotherapy given and if you’re having external or internal radiotherapy. Some possible side effects are:

  • tiredness
  • effects on the skin
  • bladder changes
  • bowel changes
  • urinary problems in men
  • effects on women, such as early menopause.

Many side effects can be managed successfully and most will begin to get better a few weeks after treatment ends. Your cancer doctor, specialist nurse or radiographer will explain the most likely side effects in your situation. Always tell them about any new symptoms.

Possible side effects during treatment

During treatment, you may have some of the side effects explained in this information. It’s important to tell your radiographer, cancer specialist or specialist nurse if you do. They can give you advice on how to manage them and tell you about the treatments that can help.


Radiotherapy often makes you feel tired, especially towards the end of the course of treatment. The tiredness continues after the treatment has finished and may last for a few months. You’ll find that your energy levels will gradually improve. However, it can take a while to recover, so don’t be too hard on yourself.

There are some things you can do to help manage tiredness:

  • Pace yourself so you don’t overdo it and take regular rests.
  • If you’re able to, plan some physical activity into your day, such as going for a short walk. This will help to build up your energy levels.
  • Ask family and friends to help out, perhaps with things like household tasks and taking care of the children.
  • Make sure you get enough sleep.

We have more information about coping with tiredness (fatigue), keeping physically active during treatment and getting a good night’s sleep.

Effects on the skin

Sometimes, radiotherapy can cause a skin reaction in the area being treated. The skin may redden or get darker, and become dry, flaky and itchy. Towards the end of treatment, the skin sometimes becomes moist and sore, and there may be breaks in the skin, especially around the back passage and groin.

Your radiographer or nurse will check your skin regularly. Tell them if your skin is sore or if you notice any other changes. They will assess your skin and may prescribe a cream or dressings to help. They can also prescribe painkillers, if needed.

Skin care

Your radiographer or specialist nurse will tell you how to look after the skin in the treated area. They will usually give you the following advice:

  • Keep the skin in the area clean, washing it gently with lukewarm water and unperfumed soap, then carefully patting it dry with a clean, soft towel.
  • Avoid using talcum powder, shower gel or any scented products on the treated area, as these can irritate the skin. Check with the radiographer or nurse before you put anything on the skin in the treated area.
  • When taking a shower, use a very gentle stream of lukewarm water. If you take a bath, don’t soak in the water for long.
  • Use a simple, unperfumed moisturiser on the skin such as aqueous cream.
  • Wear cotton or silk underwear which is loose fitting (such as boxers or shorts) which won’t rub against the skin. Avoid wearing tight-fitting trousers.
  • If you shave, wax or use hair removal creams, wait until a few weeks after radiotherapy is over and any skin reaction has healed.
  • Avoid smoking, as this can make skin reactions worse.

Skin reactions may be at their worst up to two weeks after radiotherapy finishes, before beginning to improve. If you’re sore or are having any problems with your skin during this time, contact the radiotherapy department for advice.

You’ll need to protect the skin in the treatment area from the sun for the first year after radiotherapy. After this, the skin will remain sensitive to strong sunlight, so if it is ever exposed, you should always wear suncream with a high sun protection factor (SPF) of at least 30.

Pelvic radiotherapy may make your pubic hair (hair around your genital area) fall out. It should start to grow back again within a few weeks after radiotherapy finishes, but it may be thinner. Occasionally, hair loss can be permanent.

Bladder side effects

Pelvic radiotherapy can cause irritation and inflammation of the lining of the bladder. You may find that you have some of the following symptoms:

  • a need to pass urine often (frequency)
  • a need to pass urine during the night (nocturia)
  • a burning sensation when you pass urine (similar to cystitis)
  • a feeling that you can’t wait when you find you need to empty your bladder (urgency)
  • blood in your urine (haematuria)
  • leaking small amounts of urine (incontinence).

Your doctor can prescribe painkillers or anti-inflammatory drugs to ease these symptoms. A sample of your urine may be tested to make sure there’s no infection present. If you have an infection, your doctor will prescribe a course of antibiotics for you. There are also things you can do to help with these symptoms.

What you can do

  • Drink at least 2–3 litres of fluid a day – urine that’s concentrated irritates the bladder and makes symptoms worse, so drinking more reduces this.
  • Avoid smoking, which can make the symptoms of bladder irritation worse.
  • Avoid drinks that can irritate the bladder. These include drinks containing caffeine (tea, coffee, cocoa and cola), alcohol, fizzy drinks, acidic drinks (fresh orange and grapefruit juice) and drinks with artificial sweeteners (‘diet’ or ‘light’ drinks).
  • Let your nurse or radiographer know if you leak urine (incontinence).
  • If symptoms get worse, you have a high temperature, or you feel you can’t pass urine, contact the hospital straight away.

If you have incontinence, your nurse will take a urine sample to check for signs of infection. This is a common and easily treatable cause of incontinence. They may also arrange for you to have pads if needed and give you advice on looking after your skin. If the problem doesn’t settle within a few weeks, they can refer you to a continence specialist for advice and treatment.

Just Can’t Wait toilet card

If you need to go to the toilet more often, or feel that you can’t wait when you do want to go, you can get a card to show to staff in shops, pubs and other places. The card allows you to use their toilets without them asking awkward questions.

You can get a card from the Bladder and Bowel Foundation.

Other urinary problems in men

As well as bladder irritation, radiotherapy for prostate cancer may cause irritation of the tube that carries urine from the bladder to outside the body (the urethra) and swelling of the prostate gland. In addition to symptoms such as urinary frequency and urgency, this can cause you to:

  • need to wait for the flow of urine to begin (hesitancy)
  • have a weak flow of urine
  • feel that you haven’t quite emptied your bladder.

Your doctor may prescribe anti-inflammatory drugs, steroids or alpha-blockers, which may help reduce these effects. Alpha-blockers such as tamsulosin (Flomax®), terazosin (Hytrin®) or doxazosin (Cardura®) are tablets that work by relaxing the muscle in the bladder and prostate gland.

During or after radiotherapy for prostate cancer, some men develop a sudden inability to pass urine. This is called acute urinary retention. It’s rare in men having external radiotherapy but it does sometimes occur after internal radiotherapy (brachytherapy), particularly in men who had urinary symptoms before treatment and have a larger prostate gland.

Acute urinary retention is caused by the prostate gland swelling and blocking the urethra. It may be treated with drugs that reduce swelling such as steroids or anti-inflammatory drugs (NSAIDs), or by putting a tube (catheter) into the bladder for a short time. It’s important to contact your doctor if you’re unable to pass urine.

Bowel side effects

Pelvic radiotherapy can cause some of the following side effects:

  • loose stools, diarrhoea or sometimes constipation
  • a need to open your bowels urgently
  • cramping pains in your tummy (abdomen) or back passage
  • passing a lot of wind.

Some other, less common side effects are:

  • feeling as if you need to go to the toilet although your bowel is empty (tenesmus)
  • passing mucus or blood when you empty your bowels
  • slight soiling on your underwear or some leakage (incontinence), although this is rare.

Tell your cancer specialist, specialist nurse or radiographer about any bowel side effects you have.

Diarrhoea is the most common side effect and usually starts during or after the second week of radiotherapy. If you have diarrhoea, your specialist will prescribe anti-diarrhoea tablets such as Imodium® to reduce it. Some people are advised to make changes to their diet during radiotherapy. This may involve eating a more bland diet and cutting down on fibre. Your specialist nurse or radiographer will tell you if this is appropriate for you. You’ll always be advised to drink plenty of fluids.

If you have tummy cramps, let your cancer specialist or nurse know. They can prescribe anti-spasmodic or muscle relaxant drugs to help with this. If you’re constipated, your doctor will usually prescribe a laxative and you’ll be given advice on diet.

Let your nurse or radiographer know if you have any soiling or leakage. They will give you advice on coping with this and looking after the skin. Bowel side effects usually start to improve about two weeks after radiotherapy has finished. Sometimes, it may take a few months for the bowel to settle down.

What you can do

  • Drink at least 2–3 litres of fluid a day (to replace fluid lost through diarrhoea) and avoid drinks containing caffeine and alcohol.
  • Follow any dietary advice given by the hospital.
  • Take your anti-diarrhoea tablets or other medicines as prescribed by the hospital.
  • If side effects don’t get better, let the hospital know.
  • Avoid smoking, which stimulates the bowel and can make diarrhoea worse.

Effects on women

During radiotherapy, you may have a skin reaction in the treated area, such as the vagina. We have more information on skin care.

Early menopause

Pelvic radiotherapy stops the ovaries producing oestrogen and progesterone and brings on the menopause. Early menopause as a result of radiotherapy may cause more noticeable symptoms than a natural menopause. Symptoms can include:

  • hot flushes and sweats
  • vaginal dryness
  • passing urine more often
  • lower sex drive
  • aches and pains
  • mood swings and poor concentration.

Hormone Replacement Therapy (HRT)

Your doctor may prescribe HRT to replace the hormones your ovaries are no longer producing. If you had cancer of the cervix or rectum it’s usually safe to take HRT. But some cancers, for example womb cancer, are dependent on hormones to grow, so HRT may not be advised. Ask your cancer specialist if HRT is suitable for you.

HRT can improve some menopausal symptoms and protect your bones and heart. Early menopause increases the risk of bone thinning.

Managing menopausal symptoms

If your specialist doesn’t advise HRT or you decide not to take it, there are different ways to manage your symptoms. If your symptoms are affecting your day-to-day life, ask your doctor about other medicines that may help to reduce them.

Low doses of antidepressant drugs or a drug called clonidine (Catapres®, Dixarit®) used to control blood pressure can reduce hot flushes and sweats. Some women find that slow, controlled breathing techniques or acupuncture may help with flushes. You can use lubricants or creams to help reduce vaginal dryness and make it easier to have sex.

The Daisy Network is a support organisation for women who have early menopause.

What you can do

Making lifestyle changes may help reduce some of your symptoms and improve your general health.

  • Eating healthily can make you feel better and give you more energy. Try to cut down on alcohol or caffeine, which can trigger a hot flush or affect sleep.
  • If you smoke, try to stop as it can trigger hot flushes, weaken your bones and irritate your bladder. It’s also a major risk factor for cancer and other health problems.
  • Keeping physically active helps keep your weight healthy, makes you feel better and helps you sleep better. It also strengthens your bones and protects your heart.
  • Yoga or meditation may help reduce stress and help with hot flushes.

Contact our cancer support specialists on freephone 0808 808 00 00 if you’d like more information.

Talk to your doctor or specialist nurse if you’re having these symptoms. They can give you advice and treatment that can help cope with them. The menopause also means your ovaries are no longer producing eggs, so you will not be able to get pregnant. There’s more information about this in our fertility section.

There’s a video on our website of one woman’s experience of early menopause due to cancer treatment.

Changes to the vagina

Radiotherapy to the pelvis can make the vagina narrower, less stretchy and drier. This may make having sex uncomfortable. It may also be more difficult for you to have internal examinations.

Vaginal dryness

Radiotherapy reduces the natural lubrication in the vagina, which can make having sex uncomfortable. Different creams, gels, lubricants or pessaries (small pellets that are put inside the vagina) can help with this.

If you’ve had the menopause early, hormone replacement therapy (HRT) will help with vaginal dryness. Ask your cancer specialist if HRT is suitable for you.

Oestrogen creams- Your doctor may recommend using vaginal oestrogen creams or pessaries. They help with dryness and may prevent the vaginal wall from becoming thin. Although your body will absorb some oestrogen from the cream or pessaries, many doctors think it’s too small an amount to be harmful.

Moisturising creams and lubricants -There are lots of products you can buy that help with vaginal dryness. Creams can be applied regularly to help draw more moisture into the vaginal tissue, and can be prescribed by your doctor. Lubricants help to make having sex more comfortable and pleasurable.

Replens MD® is a cream that’s available from most chemists. You apply it 2–3 times a week and it works for up to three days. Hyalofemme® is a newer cream that you can apply every day.

Water-based lubricants, including Senselle®, Astroglide®, Sylk®, Vielle® or Durex® lube, can be bought at chemists or some supermarkets. Organic lubricant products, such as Yes® or V Gel®, are available to buy online.

Vaginal dryness can make you more likely to get infections, such as thrush. Let your doctor know if you have symptoms such as vaginal itching or soreness.

Tablets, creams and pessaries to treat vaginal thrush are also available over the pharmacy counter under brand names such as Canesten®. But if you haven’t had thrush before, see your GP first. Always see your GP if you’re not sure whether it’s thrush, if symptoms don’t improve or if it keeps coming back. We have more information on treatment and ways of coping with changes to the vagina.

Vaginal narrowing

Radiotherapy can make the vagina narrower and less stretchy. The vaginal walls may also become dry and thin, and can stick together. This can make having penetrative sex with a partner now or in the future uncomfortable. It can also make having an internal examination uncomfortable. So it’s important to try to prevent the vagina from narrowing.

Your hospital team may recommend you use vaginal dilators to help. Dilators are tampon-shaped plastic tubes of different sizes that you use with a lubricant. Although they’re commonly used, there isn’t strong evidence to say how effective they are. Rarely, they may cause damage to the vagina, especially if they aren’t used correctly. Your specialist nurse or doctor will explain how best to use them in your situation.

Having regular penetrative sex, using a dildo or vibrator, or using lubricated fingers may also help prevent the vagina from narrowing. Even if you are having sex regularly, you may still be advised to use a dilator.

Most of the side effects of radiotherapy should gradually disappear once the treatment has finished. But it may take some time to recover. Looking after yourself by getting enough rest and gradually increasing your physical activity will help with your recovery.

Your cancer specialist or nurse may give you specific advice to help with your recovery. For example, you may be given information on when you can expect to go back to work, and on how to gradually build up your activities. There’s more information in our well being and recovery section.

Back to Pelvic radiotherapy explained

The pelvis

Information on the pelvic area of the body.

Fertility and pelvic radiotherapy

Pelvic radiotherapy can affect your fertility. This can be distressing but getting the right support can help you to find ways of coping.