Side effects of chemotherapy

Chemotherapy drugs can cause unpleasant side effects. However, these are mostly temporary and there are often ways of controlling or reducing them. The main areas of the body that are affected are those where normal cells rapidly divide and grow. These include cells in the mouth, the lining of the digestive system, the skin, hair follicles and the bone marrow.

Different people will be affected by chemotherapy in different ways. You will not have all of the side effects described here, but may have some of them. Your doctor or nurse will tell you more about the side effects that are likely to occur during your treatment, and ways of managing them.

Feeling tired

During treatment (and for a while afterwards) you may have less energy than usual. Tiredness often builds up as the treatment goes on. It usually gets better when treatment ends, but it can take a few months for your energy levels to recover.  

Sometimes your doctor can treat whatever is causing your tiredness, such as a low number of red cells in your blood (anaemia). So it is important to tell your doctor if you are feeling tired.  

If you feel tired, get plenty of rest. Try to pace yourself and don’t do too much. It is also important to try to do some gentle exercise, like short walks. Being active increases your energy levels and helps keep up your muscle strength.  

There may be days during a cycle of chemotherapy when you feel very tired and other days you have more energy. You may have more energy to do things you enjoy on the days before your next cycle of treatment is due to start. 

If you feel able to go out with your friends, there is no reason why you can’t. But be careful to avoid crowded places on the days you are at more risk of getting an infection. Your nurse can tell you about this.  

Let your friends know that you might have to cancel plans at short notice if you are not up to it. You can ask them to keep in touch through social media or texts so you don’t feel left out.  

If you are studying, you may need to take time away from school, college or university. Talk to your doctor or chemotherapy nurse about this. Your school or college may be able to send you work, so you can carry on studying whilst you are at home or in hospital. 

Risk of infection

This treatment can reduce the number of white blood cells in your blood. These cells fight infection. If the number of white blood cells is low, you are more likely to get infections. A low white blood cell count is called neutropenia. 

If you have an infection, it is important to treat it as soon as possible. Contact the hospital straight away on the 24-hour contact number you have been given if: 

  • your temperature goes over 37.5ºC (99.5ºF) 
  • you suddenly feel unwell, even with a normal temperature 
  • you have symptoms of an infection. 

Symptoms of an infection include: 

  • feeling shivery 
  • a sore throat 
  • a cough 
  • diarrhoea 
  • needing to pass urine often.  

It is important to follow any specific advice your cancer treatment team gives you. 

The number of white blood cells will usually return to normal before your next treatment. You will have a blood test before having more treatment. If your white blood cell count is low, your doctor may delay your treatment for a short time.  


This treatment can reduce the number of red blood cells in your blood. These cells carry oxygen around the body. If the number of red blood cells is low, you may be tired and breathless. Tell your doctor or nurse if you feel like this. If you are very anaemic, you may need a drip to give you extra red blood cells. This is called a blood transfusion. 

Brusing and bleeding

This treatment can reduce the number of platelets in your blood. Platelets are cells that help the blood to clot. Tell your doctor if you have any bruising or bleeding that you can’t explain. This includes: 

  • nosebleeds 
  • bleeding gums 
  • tiny red or purple spots on the skin that may look like a rash. 

Some people may need a drip to give them extra platelets. This is called a platelet transfusion. 

Feeling sick (nausea)

Some chemotherapy drugs can make you feel sick (called nausea) or sometimes be sick (vomit). If your treatment might make you feel sick, you will be given anti-sickness drugs before having it. You can have the drugs as a tablet or put into the vein. Your doctor might also give you drugs called steroids, to help prevent sickness.   

Make sure you take anti-sickness drugs exactly as your nurse has told you to, even if you do not feel sick. It is easier to prevent sickness than to treat it once it has started. Contact the hospital if you feel sick or if you are sick. If one anti-sickness drug does not work for you, your doctor can give you another type.  


Some chemotherapy drugs can cause diarrhoea. This often starts a few days after you have the treatment. If you are taking chemotherapy tablets or capsules at home, it is important to tell your doctor or nurse if you have diarrhoea. They may have to stop your treatment for a time or give you medicine to help. It is important to drink plenty of fluids if you have diarrhoea. 


Some chemotherapy drugs, anti-sickness drugs and painkillers can make you constipated. Let your nurse or doctor know if this happens. They can give you drugs to treat it. 

If you are constipated, eating more fibre (cereals, raw vegetables and fruits) and drinking plenty of liquid can help. Gentle exercise, such as short walks, can also help. 

Sore mouth

Your mouth may get sore or dry. You may get small ulcers in your mouth during treatment. Some people find that sucking ice soothes the soreness. Drink plenty of fluids, and clean your teeth regularly with a soft toothbrush. This will help to reduce the risk of a sore mouth and help it to recover more quickly. Tell your nurse or doctor if you have any mouth problems. They can give you mouthwashes and medicine to prevent or clear mouth infections. 

Taste changes

You may get a bitter or metal taste in your mouth. Sucking sugar-free sweets may help with this. Some foods may taste different or have no taste. Try different foods to find out what tastes best to you. Taste changes usually get better after treatment finishes. Your nurse can give you more advice. 

Poor appetite

Some people lose their appetite when they are having chemotherapy. This can be mild and may only last a few days. If your appetite does not improve, tell your chemotherapy nurse. They can arrange for you to see a dietitian. 

Hair loss

Some chemotherapy drugs make your hair fall out. Sometimes, hair gets thinner or becomes dry and breaks easily. Your doctor or nurse will be able to tell you if you are likely to lose your hair.  

Hair loss usually starts within a few weeks of starting treatment. Rarely, it can start after a few days. As well as the hair on your head, you may lose body hair and your eyelashes and eyebrows.  

Losing your hair can be tough to cope with. Your hair will usually grow back again once you have finished treatment. There are lots of ways you can cover up until then. Talk to your nurse about your options. You can use baseball caps, beanies, hats, wigs, bandanas or scarves. Or you might choose to shave your head and not cover up – it’s your choice. 

Some wigs can look a lot like your own hair. If that’s what you want, it’s a good idea to have one fitted before you lose your hair, so that you can get a close match. Or you might want to try something completely different. You can usually get a wig on the NHS and your usual hairdresser can style it for you.  

You might want to have your hair cut short before you start chemotherapy. This is because the weight of long hair pulling on the scalp can make it fall out faster. When you start to lose your hair, you can wear a soft hat or a turban at night to help collect any loose hair.  

Here are some tips for looking after your hair if it thins and when it is growing back:  

  • Use gentle hair products and pat hair gently with a towel to dry it after washing.  
  • Avoid using hairdryers, straighteners or other heated hair tools.  
  • Use a brush with wide prongs or a wide-toothed comb, and be gentle when brushing your hair.  
  • If your hair breaks easily, or your scalp is dry and itchy, do not dye your hair. Wait until it is in better condition. When it is, use a vegetable-based colourant –ask your hairdresser for advice.  

We have more information about hair loss in our section on coping with changes to your body.

Risk of blood clots

Cancer can increase your risk of developing a blood clot (thrombosis) in your leg or chest. Having chemotherapy may also increase this risk.  

A blood clot may cause symptoms such as: 

  • pain, redness and swelling in a leg 
  • breathlessness and chest pain. 

Blood clots can be very serious if they are not treated. Always contact the hospital immediately on the 24-hour contact number you have been given if you have any of these symptoms. A doctor will treat the clots with drugs to thin the blood. Your doctor or nurse can give you more information about blood clots. 

Changes in how your kidneys work

Some chemotherapy drugs can affect how well your kidneys work. If you are having one of these drugs, you will have a blood test before each treatment to check your kidneys are working well. You will be given fluid through a drip (infusion), before and after the treatment, to keep your kidneys working normally. The nurses may ask you to drink plenty of fluid and to record what you drink and the amount of urine you pass. 

Numb or tingling hands or feet

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

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

Skin changes

Some chemotherapy drugs can affect your skin. They can make your skin dry or itchy, slightly discoloured, or can cause a rash. Use a perfume-free moisturiser to keep your skin soft and well-moisturised. Let your nurse know about any skin changes you notice.  

Your skin might also be more sensitive to sunlight during and after chemotherapy treatment. Protect yourself from the sun by wearing loose clothing, a hat and high-factor sunscreen (at least SPF 30) on exposed skin.  

Changes in hearing

Some chemotherapy drugs, such as cisplatin, can affect your hearing. You might not be able to hear high-pitched sounds as well as you could before. Or you might have a high-pitched ringing in your ears (called tinnitus). Any hearing loss can be permanent, but tinnitus usually improves when your treatment ends.  


Some chemotherapy drugs can cause changes to fertility (being able to make someone pregnant or get pregnant). Your doctor or nurse should talk to you about this before you start cancer treatment. If there is a risk that chemotherapy will affect your fertility, they will talk to you about treatment called fertility preservation. 

Link to further information

Late effects

Chemotherapy can help to cure cancer, but may sometimes cause long-term side effects or health problems years after treatment. These are called late effects. Doctors are researching ways to prevent or reduce the chances of late effects. 

It is important to have a healthy lifestyle after treatment, including exercising regularly and not smoking. Having a healthy lifestyle can reduce the risk of problems. Your doctor will talk to you about this.  

After your chemotherapy is over, you will come back to the clinic for check-ups, usually for many years. This means any health problems linked to the treatment you had can be picked up and treated early. Possible late effects depend on the type of treatment you had and the dose of chemotherapy drugs you had. Your cancer doctor and specialist nurse will talk to you about any possible late effects.  

Link to late effects section