Possible side effects of chemotherapy

Chemotherapy treatment can cause different side effects. These vary depending on the drugs you have. If you’re having a single drug, you may not have as many side effects as someone having a combination of drugs. People having high doses of chemotherapy may have more complex side effects.

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 areas where new cells are being quickly made and replaced. This includes the:

  • bone marrow (where blood cells are made)
  • hair follicles (where hair grows from)
  • digestive system
  • lining of your mouth.

Your cancer doctor and nurse specialist will explain the side effects that your chemotherapy is likely to cause. Most side effects can be reduced and controlled with drugs. Your doctor or nurse can tell you how to manage them.

Most side effects stop or gradually go away when chemotherapy is over. Although the side effects can be unpleasant, the benefits of chemotherapy usually outweigh this.

Possible side effects

The side effects you get will depend on the chemotherapy drugs you’re having. Different drugs cause different side effects. You may get some of the side effects mentioned, but you are very unlikely to get all of them.

Some side effects are mild and easily treated. Your doctor, nurse or pharmacist may prescribe drugs to help control them. It is very important to take the drugs exactly as instructed. This means they will be more likely to work for you. Other side effects can be harder to manage but can often be reduced or helped in some way. Your nurse will give you advice about this.

Most side effects stop or gradually go away when chemotherapy is over. Although the side effects can be unpleasant, the benefits of chemotherapy usually outweigh this.

If you’re having a single drug, you may not have as many side effects as someone having a combination of drugs. People having high doses of chemotherapy may have more complex side effects.

Your cancer doctor and nurse specialist will explain the side effects that your chemotherapy is likely to cause. The main areas of your body that may be affected by chemotherapy are areas where new cells are being quickly made and replaced. This includes the:

  • bone marrow (where blood cells are made)
  • hair follicles (where hair grows from)
  • digestive system
  • lining of your mouth.

Your bone marrow and blood

Chemotherapy can reduce the number of blood cells made by the bone marrow. Bone marrow is a spongy material that’s found in the middle of your bones. It makes special cells called stem cells which develop into the different types of blood cells:

  • white blood cells, which fight and prevent infection
  • red blood cells, which carry oxygen to all parts of the body
  • platelets, which help the blood to clot and prevent bleeding and bruising.

You’ll have regular blood samples taken to check the number of these cells in your blood (called a full blood count).

Risk of infection

If the number of your white blood cells is low, you’re more likely to get an infection. The main white blood cells that fight infection are called neutrophils. When they are low, you are neutropenic.

Your resistance to infection is usually at its lowest 7–14 days after chemotherapy. The number of your white blood cells will then increase steadily and usually return to normal before your next cycle of chemotherapy is due.

A photo of Stuart talking about neutropenic sepsis

Neutropenic sepsis

Stuart talks about he how coped with neutropenic sepsis, an infection which can be a side effect of chemotherapy.

About our cancer information videos

Neutropenic sepsis

Stuart talks about he how coped with neutropenic sepsis, an infection which can be a side effect of chemotherapy.

About our cancer information videos


Developing an infection when your white blood cell count is low can sometimes be a serious complication of chemotherapy.

Although this may sound scary, most people don’t have any serious problems with infection. Some chemotherapy treatments are more likely than others to reduce your white blood cell count. Your doctor may prescribe you antibiotics and other medicines to take during chemotherapy to prevent an infection. These are called prophylactic drugs.

Even a mild infection can delay your chemotherapy treatment. Your doctor may wait until the infection has gone and for your blood count to go back up before you continue with treatment.

Your chemotherapy nurse will talk to you about infection and show you how to check your temperature. Most hospitals consider a temperature above 38°C (100.4°F) to be high, although some hospitals use a lower temperature.

You can have an infection without showing a high temperature. Drugs, such as paracetamol, lower your temperature so they can hide or ‘mask’ an infection.

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

  • your temperature goes over 37.5°C (99.5°F)
  • you suddenly feel unwell, even with a normal temperature
  • you have any symptoms of an infection such as a cold, sore throat, cough, passing urine frequently (urine infection), diarrhoea or feeling shivery and shaking.

Chemotherapy units usually have a policy they follow when someone with low white blood cells has an infection. This is to make sure you get treatment with antibiotics straight away to prevent any complications.

Some people may have to stay in hospital to have antibiotics given into a vein (intravenously). After a few days, you can usually have them as capsules or tablets to take at home.


After chemotherapy, your nurse may give you injections of a drug called G-CSF under the skin. This encourages the bone marrow to make more white blood cells and reduces the risk of infection.

Helpful hints – avoiding infection

  • Keep clean and always wash your hands thoroughly after using the toilet or before preparing food.
  • Stay away from crowded places and from people who you know have an infection, such as a cold.
  • Make sure your food is thoroughly cooked, and ask your nurse if there are any foods you should avoid.

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. After this you will have more energy and feel less short of breath.

In certain situations, doctors may prescribe a drug called erythropoietin to treat anaemia. It is given as an injection under the skin. But it’s more common to have a blood transfusion for anaemia.

Increased bleeding and bruising

If the number of platelets in your blood is reduced you may bruise very easily, or bleed more than usual from minor cuts or grazes.

Tell your hospital doctor or nurse about this and contact them straightaway if you notice or have:

  • nosebleeds
  • bleeding gums
  • tiny red or purple spots on the skin (petechiae) that sometimes cluster to make a rash.

Helpful hints – avoiding injuries

If your platelets are low you’ll need to be careful to avoid injuries.

  • Wear protective gloves when doing work around the house or in the garden.
  • Be careful to avoid bumping into things or tripping.
  • Use a soft toothbrush to protect your gums from bleeding and don’t floss.

Some people may need a platelet transfusion. This is given by drip (infusion) as a day patient. The platelets will start working immediately to prevent bruising and bleeding.

Your hair

Your doctor or specialist nurse will tell you if the chemotherapy is likely to cause hair loss. Knowing what to expect gives you time to prepare and find ways of coping.

Some drugs don’t make your hair fall out but can make it thinner. You might notice your hair becomes dry and brittle and breaks easily. Looking after the condition of your hair can make it less likely to break off.

Helpful hints – looking after your hair

  • Use gentle hair products, pat hair dry after washing it and gently brush with a wide-toothed comb.
  • Avoid using hairdryers, straighteners, tongs or curlers.
  • Don’t perm or colour your hair if it’s brittle or your scalp is dry – if you do want to do this, make sure you get professional advice first.
  • If you want to colour your hair, use a mild vegetable-based colourant (do a strand test first), and ask your hairdresser for advice.

Scalp cooling

Some people having certain types of chemotherapy may be able to prevent hair loss by using a ‘cold cap’. This works by temporarily reducing the blood flow and the amount of the drug reaching the scalp. But the cold cap only works with certain drugs and types of cancer and doesn’t always prevent hair loss. You can ask your doctor or nurse whether one would be useful for you.

Losing your hair

Some chemotherapy drugs cause all or most of your hair to fall out, which can be very upsetting. There are lots of ways you can cover up, if you choose to, such as using wigs, hats, turbans, scarves or bandanas.

Hair loss usually starts within a few weeks of starting chemotherapy or, very occasionally, within a few days. You usually notice your hair coming out more when you brush, comb or wash it, and you may find hair on your pillow in the mornings.

You may lose underarm, body and pubic hair as well. Some chemotherapy drugs also make the eyelashes and eyebrows fall out.

Your hair will usually grow back over a few months once you’ve finished treatment. It will be very fine at first and may be a slightly different colour or texture than before. You’ll probably have a full head of hair after 3–6 months. To begin with, you should try to look after the condition of your hair.

Helpful hints – coping with hair loss

  • Cutting hair short before chemotherapy can stop the weight of long hair pulling on the scalp, which can make hair fall out earlier.
  • Wearing a hairnet, soft cap or turban at night stops your hair becoming tangled and helps to collect loose hair.
  • You can ask your own hairdresser to cut and style your wig for you.


If you are choosing a wig, here are some tips:

  • Match the wig to the volume and colour of your natural hair.
  • Get the wig fitted before you lose your hair so you can get used to wearing the wig.
  • Get a wig with an adjustable size.
  • Think about whether you want to try a different hair style from the one you have.

There are different options for paying for your wig:

  • NHS wigs are free in Scotland and Wales, and for people of a certain age or on a low income in England.
  • Health Service wigs are free in Northern Ireland.
  • If you’re not entitled to a free wig, you can get one from the NHS at a subsidised price.
  • You may want to buy a wig privately. You shouldn’t have to pay VAT on your wig if your hair loss is caused by cancer.

I thought a wig was a thing you put on your head and it was all hot and horrible. But there was lots of choice.

Medha, affected by hair loss

Your digestive system

Your digestive system (stomach and bowels) can be affected in different ways by chemotherapy.

Feeling sick (nausea)

Some chemotherapy drugs can make you feel sick (nauseous), or be sick (vomit). Not all drugs cause sickness and many people have no sickness at all. There are very effective treatments to prevent and control sickness.

Anti-sickness drugs

If your chemotherapy is known to cause sickness, you’ll be given anti-sickness drugs by injection or tablets before your chemotherapy. You’ll also be given tablets to take at home afterwards. Take these regularly, even if you don’t feel sick, and exactly as your doctor has prescribed them. It’s easier to prevent sickness than treat it once it’s started.

Contact your doctor or nurse at the hospital if:

  • the anti-sickness drugs don’t stop you feeling or being sick – other drugs can be prescribed
  • if you’re being sick and aren’t able to drink enough fluids
  • the anti-sickness drugs make you constipated.

If you can’t keep down tablets, your doctor can prescribe injections or suppositories to take until the sickness is controlled.

Have a small meal a few hours before chemotherapy but not just before it. If you’re managing to eat well in between treatments, don’t worry if you can’t eat much for a couple of days after chemotherapy.

Helpful hints – feeling sick

  • Try eating dry food, such as toast or crackers, first thing in the morning.
  • Ginger can help reduce feeling of sickness – try crystallised ginger, ginger tea or ginger biscuits.
  • Sipping a fizzy drink can help – try mineral water, ginger beer or ale, lemonade or soda water and sip slowly through a straw.
  • Avoid fried, fatty foods or foods with a strong smell.
  • Eat cold food if the smell of cooking bothers you.
  • If possible, let someone else cook or prepare food for you.

Some complementary therapies such as acupuncture may help but ask your cancer doctor first. Some people find ‘Sea-bands’ helpful. They use acupressure to help relieve nausea. You can buy them in a chemist.


Some chemotherapy drugs can cause diarrhoea usually in the first few days. Let your nurse or doctor know if this happens. They can prescribe medicine to reduce this.

Make sure you drink plenty of liquid (up to two litres a day) to replace fluid you’re losing with diarrhoea. Eat less fibre (cereals, raw fruits and vegetables) until the diarrhoea improves.

Sometimes diarrhoea can be more severe and it’s important to contact the hospital if this happens. If you have more than 4–6 episodes of diarrhoea a day, contact the hospital on the telephone numbers you’ve been given and speak to a doctor or nurse.


Some chemotherapy drugs, anti-sickness drugs and pain killers can cause constipation. Let your nurse or doctor know if this happens so they can prescribe drugs to prevent or treat this.

Try to eat more fibre, raw fruits, cereals and vegetables and drink plenty of liquid. Gentle exercise, such as short walks, can help to improve constipation.

Loss of appetite

Chemotherapy can affect your appetite. If you have a poor appetite, try to eat little amounts as often as possible. Keep snacks, such as nuts, grated cheese or dried fruit, handy to eat whenever you can.

It’s important to try to eat well during your treatment. If you’re having problems, ask your nurse for advice and you can also ask to see a dietitian.

You can add extra energy and protein to your diet with everyday foods or by using food supplements.

Taste changes

You may find that your sense of taste changes, or that the texture of food seems different. This may be due to the cancer, or it can be a temporary change following cancer treatment. You may no longer enjoy certain foods, or find that all foods taste the same. Some people having chemotherapy notice a metallic taste in their mouth. Others find that food has no taste at all.

Helpful hints – changes to sense of taste

  • You might find cold foods taste better than hot foods.
  • Sharp-tasting fresh fruit/juices or boiled sweets can leave a pleasant taste in the mouth.
  • Use seasoning, spices and herbs to flavour cooking.
  • Try marinating food or use strong-flavoured sauces.

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.

Always let your doctor or chemotherapy nurse 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.

Helpful hints – taking care of your mouth

  • Clean your teeth or dentures gently every morning, evening and after meals using a soft-bristled or children’s toothbrush and rinse your mouth regularly with salt water.
  • If your toothpaste stings or brushing your teeth makes you feel sick, try using a mouthwash of one teaspoon of bicarbonate of soda dissolved in a pint (570mls) of warm water.
  • If your doctor or nurse gives you a mouthwash, use it as prescribed to prevent soreness.
  • Gently use dental tape or floss once a day (unless you have low platelets).
  • Keep your lips moist by using Vaseline® or a lip balm.

Helpful hints – if your mouth is sore

  • Try to drink at least 3 pints (1.5 litres) of fluid a day (including water, tea, weak coffee and soft drinks).
  • Avoid hot spices, garlic, onion, vinegar and salty food.
  • Add gravies and sauces to your food to keep your mouth moist and make swallowing easier.
  • Avoid unmixed alcoholic drinks (such as vodka and whisky), tobacco and acidic drinks such as orange and grapefruit juice.


Some people feel very tired during chemotherapy. This is normal. It can be very frustrating and difficult to cope with, especially for people who normally have a lot of energy. The hardest time may be towards the end of the course of chemotherapy.

Managing tiredness

  • Try to cut down on things you don’t really need to do. Family and friends are often keen to help with things like shopping, household jobs or gardening.
  • If you have children, ask for help looking after them when you have chemotherapy and for a couple of days after. Some people may need extra childcare help and a social worker can usually arrange this for you.
  • Make sure you get plenty of rest. But try to take some gentle exercise, such as short walks or more if you feel up to it. This will give you more energy and helps to keep some of your muscles working.
  • Some people carry on working during chemotherapy. Most employers will reduce your hours and change work duties to make things easier for you.
  • If you’re having difficulty sleeping, we have information about managing sleep problems.

The tiredness will get easier when chemotherapy is over. But it can be three or four months until you feel back to normal. Some people find that they still feel tired a year or so afterwards.

Your skin

Some drugs can affect your skin. It may become dry or slightly discoloured. Chlorine in swimming pool water can make this worse. Your skin may also be more sensitive to sunlight, during and after treatment.

Tell your cancer doctor or nurse if you develop any skin changes or rashes.

Helpful hints – skin changes

  • Avoid wet shaving – an electric razor is less likely to cause cuts.
  • Use moisturising cream if your skin is dry or itchy, but check with your nurse before using creams if you’re also having radiotherapy.
  • If you’re out in the sun, wear a high sun protection factor (SPF) suncream of at least SPF 30.

Nail changes

Your nails may grow more slowly or break more easily. You may notice white lines across your nails, or other changes to their shape or colour. Once the treatment has ended, any changes usually take a few months to grow out.

There are things you can do to look after your nails:

  • Keep your nails and hands moisturised.
  • Wear gloves to protect your nails when you are doing things in the house or garden.
  • Do not use false nails during this treatment. It is fine to wear nail varnish.
  • If your toenails are affected, wear well-fitted shoes to cushion them.

Effects on the nerves

Some chemotherapy drugs can affect the nerves in your hands or feet. This can cause tingling or numbness, or a feeling like pins and needles. This is called peripheral neuropathy.

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

Effects on the nervous system

Some drugs can make you feel anxious, restless, dizzy, sleepy or have headaches. If you have any of these it’s important to let your cancer doctor or nurses know. They may be able to prescribe medicines that can help with some of these effects.

Some cancer treatments, such as chemotherapy, can cause changes in memory or concentration during or after treatment. Doctors sometimes call this mild cognitive impairment (MCI) but it’s more usually known as ‘chemo brain’ or ‘chemo-fog’. Problems in concentrating and memory can also be caused by anxiety and depression.

If this happens, it’s usually mild. There are useful ways of managing it, such as using lists, post-it notes, calendars and your mobile phone for reminders. Doing some mental exercises, eating well, and getting enough rest can also help.

Changes in how your kidneys work

Some chemotherapy drugs can affect how well your kidneys work (kidney function).

Before each treatment your kidneys will be checked with a blood test. You’ll 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.

Changes in hearing

Some chemotherapy drugs can affect your hearing. You may have ringing in the ears (tinnitus) and lose the ability to hear some high-pitched sounds. Very occasionally your sense of balance may be affected. Any hearing loss and changes in balance may be permanent. Tinnitus usually improves when treatment ends.

Tell your cancer doctor or nurse if you notice any of these changes.

Increased risk of blood clots

Cancer can increase your risk of developing a blood clot (thrombosis), and having chemotherapy may increase this risk further. A blood clot may cause symptoms such as pain, redness and swelling in a leg, or breathlessness and chest pain.

Blood clots can be very serious, so it’s important to tell your doctor straightaway if you have any of these symptoms. However, most clots can usually be successfully treated with drugs to thin the blood. Your doctor or nurse can give you more information about blood clots.

I do like to think that the side effects are an indication that the chemo was doing its job and killing the bad as well as some of the good.


Back to Side effects of chemotherapy

Late effects of chemotherapy

Late effects are side effects you still have 6 months after chemotherapy or side effects that begin years later.