Possible side effects

Chemotherapy treatment can cause side effects, which may vary depending on the chemotherapy drugs you have. Most side effects can be reduced with medicines and usually go away once the treatment has finished.

Some side effects are more common than others but you won’t have them all. The main areas of your body that may be affected by chemotherapy are:

  • bone marrow (where blood cells are made), causing an increase in the risk of infection, anaemia, bruising and bleeding
  • digestive system, causing a feeling of sickness, loss of appetite and diarrhoea
  • lining of your mouth, causing a sore mouth
  • hair follicles (where hair grows from), causing possible temporary hair loss.

Other possible side effects may include:

  • tiredness
  • sore hands and feet
  • numbness and tingling in the hands and feet.

Your cancer doctor and nurse specialist will explain the side effects that your chemotherapy is likely to cause and how to manage them.

Side effects

Chemotherapy drugs may cause unpleasant side effects, but these can usually be well controlled with medicines and will usually go away once treatment has finished. Not all drugs cause the same side effects and some people may have very few. You can talk to your doctor or nurse about what to expect from the treatment that’s planned for you.

Risk of infection

Chemotherapy can reduce the number of white blood cells, which help fight infection. If the number of your white blood cells is low you'll be more prone to infections. A low white blood cell count is called neutropenia.

Always contact the hospital immediately on the 24-hour contact number you've been given and speak to a nurse or doctor if:

  • you develop a high temperature – this may be over 37.5ºC (99.5ºF) or over 38ºC (100.4ºF) depending on the hospital's policy. Follow the advice that you have been given by your chemotherapy team
  • you suddenly feel unwell, even with a normal temperature
  • you feel shivery and shaky
  • you have any symptoms of an infection such as a cold, sore throat, cough, passing urine frequently (urine infection), diarrhoea.

If necessary, you'll be given antibiotics to treat any infection. You'll have a blood test before each cycle of chemotherapy to make sure your white blood cells have recovered. Occasionally, your treatment may need to be delayed if the number of your white blood cells is still low.

We have information about avoiding infections.

Feeling sick or being sick

Some chemotherapy drugs can make you feel sick (nauseated) or possibly be sick (vomit). Your cancer specialist will prescribe anti-sickness (anti-emetic) drugs to prevent this. Let your doctor or nurse know if your anti-sickness drugs are not helping, as there are several different types you can try. We have more information about controlling nausea and vomiting.


Some chemotherapy drugs can cause diarrhoea. Your doctor can prescribe drugs to control this. Make sure you drink plenty of fluids if you have diarrhoea.

If you’re taking capecitabine tablets at home, it’s important to let your doctor or nurse know if you have diarrhoea.

Sometimes, your treatment may need to be interrupted.

Sore hands and feet

This is sometimes known as palmar-plantar erythema or hand-foot syndrome. It can be caused by capecitabine or 5FU and will improve when the treatment is finished. Your doctor or nurse can give you advice and prescribe creams to improve the symptoms. It can also help to keep your hands and feet cool, and to avoid tight-fitting clothing, such as socks, shoes and gloves.

Mouth problems

Chemotherapy can cause different mouth problems, such as a sore mouth, mouth ulcers or infection. Your chemotherapy nurse will explain how to look after your mouth to reduce the risk of problems.

Some chemotherapy drugs can make your mouth sore and you may get mouth ulcers about 5–10 days after they’re given. Mouth ulcers can become infected or you may develop an infection in your mouth called thrush.

Always let your doctor or chemotherapy nurse or know if you have mouth ulcers, or any problems with your mouth. They can give you mouthwashes, medicines and gels to heal ulcers and clear or prevent any infection.

The most common mouth infection is called thrush (or candidiasis). It shows as white spots on your mouth and tongue, or your tongue and mouth lining become red and swollen. Thrush is treated with anti-fungal tablets. Some people are prescribed these tablets to prevent thrush.

It’s a good idea to see your dentist before you start treatment. Dental treatment may need to be delayed during chemotherapy because of the risk of infection and a sore mouth.

Anaemia (reduced number of red blood cells)

If chemotherapy reduces the number of red blood cells in your blood, you may become very tired and feel you have no energy. You may also become breathless and feel dizzy and light-headed. These symptoms happen because the red blood cells contain haemoglobin, which carries oxygen around the body.

If your haemoglobin is low you may be offered a blood transfusion. You’ll feel more energetic and any breathlessness will be eased.

Bruising and bleeding

Chemotherapy can reduce the number of platelets in your blood. Platelets are cells that help the blood to clot. If you develop any unexplained bruising or bleeding, such as nosebleeds, bleeding gums, blood spots or rashes on the skin, contact your doctor or the hospital straight away.

Hair loss

Some chemotherapy drugs may cause hair loss. Some people may have complete hair loss including eyelashes and eyebrows. Others may only experience partial hair loss or thinning. It depends on what chemotherapy drugs you are having (your doctor or nurse can tell you more about what to expect). If you do experience hair loss your hair should start to grow back within about 3–6 months of the end of treatment. It may grow back straighter, curlier, finer, or a slightly different colour than it was before. Your nurse can give you advice about coping with hair loss and how to look after your scalp.

Some chemotherapy departments may offer scalp cooling to reduce hair loss during chemotherapy. We have more information about coping with hair loss.

Effects on the nerves

Some chemotherapy drugs can affect the nerves in your hands or feet. This can cause tingling or numbness, a sensation of pins and needles or muscle weakness (called peripheral neuropathy).

It’s important to let your doctor know if this happens. They may need to change the chemotherapy drug if it gets worse. Usually, peripheral neuropathy gradually gets better when chemotherapy is over but sometimes it’s permanent.

Tiredness (fatigue)

You’re likely to become tired and have to take things slowly. Try to pace yourself and save your energy for things that you want to do or that need doing. Balance rest with some physical activity – even going for short walks will help increase your energy levels. We have helpful tips on coping with tiredness.

Effects on fertility

Some chemotherapy drugs can affect your ability to become pregnant or father a child. If this concerns you, it’s important to talk about it with your cancer doctor before you start chemo-therapy.

Early menopause

Women may find that chemotherapy causes an early menopause. This can cause menopausal symptoms such as hot flushes and sweats. Your doctor can prescribe hormone replacement therapy (HRT) to help with this. You can talk this over with your cancer doctor or specialist nurse.

Sex and contraception

Doctors will advise you to use condoms for a few days after chemotherapy to protect your partner from the drugs. It’s important to use contraception during treatment and for a few months after.

It’s not advisable to become pregnant or father a child while having chemotherapy as the drugs may harm the unborn baby. You can discuss this with your doctor or specialist nurse.

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