Chemotherapy side effects

Like any treatment, chemotherapy can cause side effects. Everyone reacts differently to drugs and some people have more side effects than others. These side effects can usually be managed and those described here will not affect everyone.

Your treatment team will give you information about the drugs you’re having, details of any side effects they may cause and how these can be controlled or managed.

You should be given a 24-hour contact number or told who to contact if you experience any side effects at any time during your treatment. This includes at night or at the weekends.

Before each cycle of chemotherapy, you’ll have an assessment to see how you’re feeling and whether you’ve had any side effects.

If you’re concerned about any side effects, regardless of whether they’re listed here, talk to your treatment team as soon as possible.

Chemotherapy can temporarily affect the number of blood cells in the body. Blood is made up of red cells, white cells and platelets.

You’ll have regular blood tests. If these show the number of blood cells is too low, your next cycle of treatment may be delayed or the dose of chemotherapy reduced.

Your treatment team may change the dose of a drug to suit you and help manage its side effects.

Risk of infection

Not having enough white blood cells can increase your risk of getting an infection. The number of white blood cells usually returns to normal before your next cycle of chemotherapy is due.

You should be given a 24-hour contact number or told who to contact if you feel unwell at any time during your treatment, including overnight or at the weekends.

You may need treatment if you get an infection.

Sometimes your treatment team may recommend injections of drugs called growth factors. This helps the body produce more white blood cells to reduce your risk of infection.

Anaemia

Having too few red blood cells is called anaemia. If you feel breathless, dizzy or particularly tired, let your treatment team know.

Bruising and bleeding

Chemotherapy can reduce the number of platelets, which help the blood to clot. If your platelets are low, you may:

• Bruise more easily
• Have nosebleeds
• Notice that your gums bleed when you brush your teeth
• Take longer to stop bleeding if you cut yourself

Tell your treatment team if you have any of these symptoms.

People with breast cancer have a higher risk of blood clots. Having chemotherapy also increases the risk of blood clots such as a DVT (deep vein thrombosis).

If you have a DVT, there’s a risk part of the blood clot could break away and travel to the lung. This is known as a pulmonary embolism (PE).

Blood clots can be life-threatening and should be treated quickly.

You may feel sick (nausea) or be sick (vomit) after having chemotherapy. This will depend on the type and dose of drugs you’re having. But it can usually be controlled with anti-sickness medication.

You may start feeling sick straight after chemotherapy, a few hours after or up to several days later. It may only last for a few hours or it might continue for a few days.

You’ll be given anti-sickness medication, as tablets or into a vein, before each cycle of chemotherapy. You’ll also be given anti-sickness tablets to take at home.

Several types of anti-sickness drugs are available. You may need to take a combination of drugs to relieve your symptoms. This may include taking a low dose of steroids for a short time.

Contact your treatment team if you have persistent nausea, sickness or have difficulty keeping fluids down, even if it happens at the weekend or during the night.

Chemotherapy can cause hair loss. It’s completely natural to find this upsetting.

How likely you are to lose your hair depends on the type and amount of chemotherapy drugs you’re given. 

Not all chemotherapy will make you lose your hair. Some drugs don’t cause any hair loss and some cause hair thinning. But others can make your hair fall out completely.

The link below contains more information about hair loss, scalp cooling, wigs and looking after your hair.

Fatigue is extreme tiredness that does not go away with rest or sleep. It’s a very common side effect of chemotherapy and may last for weeks or months after your treatment has finished.

If you think you have fatigue, tell your GP or treatment team. They can assess you and offer advice on how to manage your energy levels.

Find out more about fatigue.

Chemotherapy may affect your mouth. It can cause:

• Sore mouth and ulcers
• Dry mouth, which can also increase the risk of tooth decay
• Infection
• Bleeding gums

Looking after your mouth, including your teeth and gums, is very important during treatment.

You’ll be given mouthwash to try to reduce soreness and stop mouth ulcers developing. It’s a good idea to use a small, soft toothbrush during this time.

If you do get a mouth infection, your treatment team or chemotherapy nurse can advise you about different mouthwashes or suitable medicine.

See your dentist for a check-up before chemotherapy begins. Avoid dental treatment during chemotherapy if possible.

If you do need to have dental work during treatment, talk with your treatment team about the best time to have this.

If you’re having difficulty registering with a dentist, let your treatment team know.

If you have any mouth problems, let your chemotherapy nurse or treatment team know as soon as possible.

You may notice taste changes while having chemotherapy. Some foods may taste different, for example more salty, bitter or metallic. You may no longer like certain foods you used to enjoy.

If this is the case, speak to your treatment team. They may be able to suggest ways of managing this. Your taste should return to normal once your treatment has finished.

You can read tips on managing taste changes on our diet during breast cancer treatment page.

Pain, redness, discolouration or swelling can occur where the needle has been inserted or anywhere along the vein. Redness can be harder to see if you have black or brown skin.

Tell your chemotherapy nurse immediately if you have pain, stinging or a burning sensation around the cannula (small plastic tube) while you’re being given chemotherapy.

Chemotherapy drugs can make your skin dry or more sensitive. They can also cause rashes. Tell your treatment team as soon as possible if you develop a rash.

Some chemotherapy drugs can cause a skin reaction called hand-foot syndrome. It usually affects the palms of the hands and soles of the feet, but you may also have symptoms in other areas such as the skin on your knees or elbows.

Ask your treatment team if they recommend any particular creams for your skin before using anything on it yourself.

Chemotherapy may cause changes to the appearance of your fingernails and toenails. This can be a change in the nail colour or texture, such as ridges forming.

Nails can become more brittle and cracked. Occasionally, the nail may lift off the nail bed and fall out, but it will grow back.

As you’re more at risk of infection while having chemotherapy, it’s important to report any signs of infection to your treatment team. Signs of infection include redness or discolouration, heat, swelling or pain in or under your fingernails and toenails.

Tips to help protect your nails:

• Use hand cream to help moisturise your hands, feet and nails
• Use gloves for household chores to protect your nails
• If your toenails are affected, avoid tight-fitting shoes
• Don’t wear false nails during chemotherapy as these can lead to infection or mask the signs of it
• Avoid nail varnish as it tends to dry the nails out more, or you could try a water-based version as this is less harsh
• Keep nails short

You may have pain, numbness or tingling in your hands and feet while having chemotherapy. This is because some chemotherapy drugs can affect the nerves. This is known as peripheral neuropathy.

If you have tingling or numbness (such as difficulty doing up buttons, or difficulty feeling the difference between hot and cold water with your fingertips), speak to your treatment team so they can monitor your symptoms. 

You might find your treatment affects your ability to concentrate and makes you more forgetful.

This is sometimes called “chemo brain” or “chemo fog”, but your treatment team may call it cognitive impairment. It usually improves over time after treatment has finished, but can sometimes continue for longer.

Chemotherapy can affect your digestive system in different ways. Some people become constipated while others have diarrhoea.

Contact your treatment team if you have diarrhoea 3 or more times than usual in 24 hours.

Drink plenty of fluids to avoid dehydration.

Some chemotherapy drugs can make indigestion (discomfort or pain in your upper tummy) more likely. Some may also cause heartburn, which is a burning feeling in your lower chest.

Let your treatment team know if you have any of these side effects. They can prescribe medication to help and give you information about diet. They may also refer you to a dietitian if necessary.

You may experience menopausal symptoms as a result of chemotherapy.

You may have already been through the menopause, but having breast cancer treatment can cause you to have symptoms again.

If you have not yet reached the menopause, your periods may stop or become irregular during chemotherapy. Whether your periods return will depend on the type of drugs used, the dose given and your age.

Even if you stop having periods and experience menopausal symptoms, you may still be fertile and could become pregnant. Your treatment team will usually recommend barrier methods of contraception, such as condoms.

You can talk to your treatment team about ways of coping with any of these symptoms.

Chemotherapy causes changes in the ovaries, which can affect your ability to become pregnant (your fertility). Whether your fertility is affected depends on the type and dose of drugs used, your age and your current fertility status.

Some people stop having periods (amenorrhoea) during chemotherapy, but this may be temporary. Your periods are less likely to return after finishing chemotherapy if you’re aged 40 or above.

Some studies have shown that using hormone therapy drugs to suppress the ovaries may protect them during chemotherapy. This is because the drugs temporarily “shut down” the ovaries by stopping them from producing the hormone oestrogen, which means your periods will stop. However, we don’t know how effective this is as a method of preserving fertility. It cannot replace other methods such as egg and embryo freezing.

Conversations about fertility can be hard, especially if you weren’t expecting to think about it at this stage. It’s important to discuss any fertility concerns with your treatment team before you begin your treatment. They should offer you a referral to a fertility specialist to discuss the possibility of fertility preservation options.

Find out more about how breast cancer treatment can affect fertility.

Most chemotherapy side effects are temporary and improve once your treatment has finished.

However, you might find side effects continue after you’ve finished treatment. You may also develop side effects months or years after you’ve finished chemotherapy.

Some chemotherapy drugs can cause heart or lung problems, and some drugs increase the risk of getting another cancer in the future. These late effects are rare. Your treatment team can talk to you about the benefits of treating your breast cancer with chemotherapy compared to the risk of these rare effects occurring.

It’s completely natural to feel anxious about having chemotherapy. Many people worry about the side effects they might get. But most side effects can be controlled. You should be told what side effects to report as well as who to contact if you have any concerns or feel unwell.

Your treatment team can help with any questions you have.

On our online forum, you can find people going through treatment at the same time as you on the chemotherapy monthly threads.