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Some of the most common side effects of breast cancer treatment include feeling tired or exhausted (fatigue), pain, nausea, vomiting, diarrhoea, hair loss, low white blood cell count, and weight gain or weight loss.

Always tell your doctor or nurse about any side effects you may be having. There are supplemental treatments available they can give you that can help with the side effects – or they may want to adjust the cancer treatment.

  • Expect side effects to be worse the first few days after treatment: It is a good idea to plan for this until you know how you will feel. Do not schedule any events that you cannot cancel for the first few days after getting an intravenous treatment. Just take time to take care of yourself.

  • There is no ‘magic medicine’ that will completely take away the side effects of treatment – it’s a question of you finding what works best for you. For example, some women find that exercise and complementary therapies – such as yoga or acupuncture – are particularly helpful.

  • Not everyone experiences side effects with treatment. So if you are not having any side effects, it does not mean that your cancer treatment is not working.

  • What feels like a side effect could be a sign of the cancer growing.

What side effects may I expect from my cancer and treatment?

Side effects depend on the particular type of treatment you are receiving – and may vary from drug to drug. Also, everyone reacts differently to treatment, so you may not have the same side effects as someone else taking the same cancer drugs.

Always discuss any side effects you may be having with your oncologist and healthcare team, so they can determine whether they are the result of the treatment or the cancer itself, and find ways to help you.

If you find that the side effects of your treatment are too difficult to tolerate, please speak to your doctor immediately. It may be possible to change your treatment dose or find a different treatment that does not give you that side effect.

Common side effects

Cancer doesn’t always mean that you will have pain, but if you are having pain it is important to let your healthcare team know. They can give you drugs to help and recommend pain relief methods.

It might help to keep a record of the frequency and the severity of your pain, if it gets worse at night, or when doing specific things. Relieving your pain effectively will have a large impact on making you feel better. It can help reduce fatigue, anxiety, depression, and improve your sleep and overall well-being. If you need strong pain medication such as morphine, please do not be afraid that you may become addicted. This will not be the case if you need the drug for your pain. 

Cancer pain is usually treated with medicine and complementary therapies. 
Therapies such as acupuncture, massage therapy, and relaxation techniques can help you to control your pain. Exercise can also help.


Fatigue is so much more than feeling tired: it is complete exhaustion.

It may be related to the physical effect of the cancer itself, or a side effect of treatment. Or it may be related to changes in your sleeping patterns, and added stress and anxiety.

Tips for dealing with fatigue:

Nausea and vomiting

Untreated nausea and vomiting can make you feel very tired and can also lead to more serious problems. Tell your healthcare team if you experience these symptoms
There are many medicines available to help you control them.

Tips to reduce nausea and vomiting:


Sleeping problems and insomnia

A number of things can prevent you from having a good night’s sleep
Pain, stress, side effects of the treatment, anxiety, depression all make it worse. You may feel like you can’t sleep, or wake up frequently in the night, or wake up very early. 
This can affect your ability to function on a daily basis. Tell your doctor, as medicine can be used to help you cope.

Tips to help you sleep:


Lack of concentration and cognitive changes

This can be caused by physical or emotional changes. It may or may not be related to your treatment. 

It is important you report any problems with concentration to your healthcare team.


It is likely your hair will change if you are receiving chemotherapy as a treatment. 
Not all chemo drugs make you lose your hair, but you may experience thinning or drying-out of your hair. Even anti-hormonal therapies can lead to hair thinning. 

Having your hair fall out can be very upsetting, and it might be a good idea to cut your hair short if you know you are going to lose it. This can help you regain some control of the situation, rather than waiting for your hair to fall out. Do what feels right for you.

Who can help me with my hair loss?

Some hospitals have staff who can provide you with ideas and tips for different headwear, such as headscarves and wigs. Ask your nurse or doctor if these are available at your hospital. 

For some, but not all chemotherapies, scalp cooling may be an effective way to prevent hair loss. Ask your doctor whether this may help for your particular treatment and whether scalp cooling is offered at your clinic.

Local breast cancer support groups may also be able to direct you to beauty salons in your area. Patient support groups can provide advice and support on coping with the changes in how you look.