Following cancer treatment some people find it difficult to concentrate or they feel more forgetful. This is sometimes referred to as ‘chemo brain’ or ‘chemo fog’.

It usually improves over time after treatment has finished, but for some people it can continue. It can be very frustrating and have a big impact on daily life.

Although it’s commonly called ‘chemo brain’, some people with cancer will have changes to their memory and concentration even if they don’t have chemotherapy. This is why your specialist team is more likely to call it cognitive impairment, cognitive dysfunction or cancer-related cognitive change.


It isn’t known exactly what causes these changes to memory and concentration. Some experts think that chemotherapy may speed up the normal ageing process. But cancer itself, the impact of a diagnosis and treatment side effects such as fatigue and menopausal symptoms are also thought to play a part.

More research is needed to get a clearer picture to understand what causes it.

Who's affected?

Anyone who has had cancer treatment may be affected by ‘chemo brain’, but some people may be more likely to experience it than others. This includes people who are depressed or anxious and those who are older or less mobile.


Symptoms vary from person to person and may be quite subtle.

You may have changes in your memory, concentration, and ability to think clearly and put thoughts into action.

You may be less organised than usual and less able to focus, or have trouble finding the right words, finishing sentences or with losing your place while reading.  

What you can do

There are a few things you can do to help manage your symptoms.

Keep a diary

If you keep a diary of how you feel, it can help identify the times when you are at your best or when you have more difficulty concentrating or remembering things. You might notice that tiredness or hunger have an effect. Being aware of this can help you plan your day.

You can also write lists or put reminders in your phone of things you need to do.

Keep your brain ‘busy’

Some people find puzzles or brain training apps or computer games useful.


Stress and anxiety can affect your memory and concentration. Relaxation techniques can help to reduce stress and anxiety, including listening to calming music, practising deep breathing, listening to a relaxation CD or using an app.

Some people find using mindfulness helpful. Mindfulness is about focusing on the present moment to try to reduce stress and improve your quality of life. There are a few NHS cancer centres in the UK that offer mindfulness classes. Classes may also combine mindfulness with meditation, yoga and breathing techniques. Lots of people also practise mindfulness on their own. To get ideas about how to do this there are lots of books and websites dedicated to mindfulness, as well as apps.

Find out about mindfulness.

Getting plenty of rest and sleep can also help.

Stay active and eat well

You may find that physical activity helps to clear your head and allows you to focus better. This could be a walk, a cycle or swim – whatever you enjoy doing.

Try to eat a balanced diet.

Talk to your specialist team

Tell your specialist team about your symptoms. They may ask you some questions to confirm you’re experiencing cognitive impairment. If so, they can refer you for help or give information about local services. This may include a counsellor or support group.

Some people find cognitive behavioural therapy (CBT) helpful. CBT is a form of talking therapy that can help you change patterns of thinking and behaviour. You can find out more about it on NHS Choices.


There’s only limited evidence about whether taking particular medicines will help improve cognitive impairment, and research is ongoing. So unless you’re taking part in a clinical trial it’s unlikely that you will be prescribed any medicine.

Talk to someone who knows what it’s like

Knowing you are not alone with the side effects of cancer treatment can help you cope better with them.

You can chat to people through our online Forum, or talk to one of our trained volunteers with an experience of breast cancer through our Someone Like Me service.

You can also talk to someone on our free Helpline for support and information on 0808 800 6000.

Last reviewed: June 2016
Next planned review begins 2018

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