Cognitive Impairment (Chemo Brain)

1. What is cognitive impairment?

During and following breast cancer treatment some people find it difficult to concentrate or 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 experience changes to their memory and concentration even if they don’t have chemotherapy. For example, hormone therapy or ovarian suppression may also have this effect. This is why your treatment team is more likely to call it cognitive impairment, cognitive dysfunction or cancer-related cognitive change.

2. What causes cognitive impairment?

It isn’t known exactly what causes changes to memory and concentration following cancer treatment. 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 understand what causes it.

3. Am I at risk of cognitive impairment?

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.

4. What are the symptoms of cognitive impairment?

Symptoms vary from person to person and may not be that obvious. Some of the common symptoms include:

·         loss of short-term memory

·         finding it difficult to concentrate or think clearly

·         being unable to put thoughts into action

·         being less organised than usual

·         having trouble finding the right words or finishing sentences

Common day-to-day examples given by people with cognitive impairment include:

·         taking longer to draft an email, and not being able to find the right words first time

·         struggling with figures, such as trying to do online banking

·         double-booking social events

·         feeling like a word is on the tip of your tongue, or forgetting the names of familiar things

·         doing things twice by accident, such as feeding a pet or buying teabags

5. How is cognitive impairment treated?

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

However, there are some 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.

Set reminders for the week

You could write lists or put reminders in your phone for things you need to do. Using a weekly pill box can be helpful for remembering to take your medication, and for checking that you’ve taken it if you’re not sure.

When you do small tasks like putting things away in a cupboard, try to focus and do this slowly, so that you’re more likely to remember.

Keep your brain ‘busy’

Some people find puzzles, 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. Many people also practise mindfulness on their own – there are lots of books and websites dedicated to mindfulness, as well as apps.

You can find out more about mindfulness on the NHS website.

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 stay hydrated and eat a balanced diet.

Talk to your treatment team

Tell your treatment 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 the NHS website.

6. Cognitive impairment and work

As cognitive impairment can affect your memory and concentration, you may find it difficult to carry out your usual role at work. If you experience fatigue or depression this may also make it harder to cope. This can lead to you feeling stressed, which can make the symptoms worse. Talk to your employer if this is the case for you.

If you are going back to work and think you may need support, talk to your manager or HR team beforehand. They may be able to make adjustments such as a phased return to work, or reducing your workload.

When you return to work it can help to speak to your co-workers – they might be able to remind you to do certain tasks, or help you relearn any skills you’ve forgotten.

Occupational therapy might help employees who have cognitive impairment. You can ask your breast care nurse or GP about this. Your HR team may also be able to suggest other sources of support.

For more information about returning to work, see our web pages on breast cancer and employment.

If you are self-employed

If you’re self-employed and experiencing symptoms of cognitive impairment, it can be difficult to know where to go for help. Macmillan has information and support about self-employment and cancer, including a booklet and web pages.

7. Further support

Cognitive impairment can be difficult to cope with, and many people feel frustrated and as if they’re not in control.

It can help to talk to someone who has been there. You can chat to people on 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 call our free Helpline and talk to one of our experts on 0808 800 6000 for more information and support.

Last reviewed: April 2019

Next planned review begins 2021

Posted in: In Treatment, Side Effects