Cognitive impairment (chemo brain)

Cognitive function is our ability to think. It involves memory, language, attention, planning, multitasking, and our response to situations.

Some cancer treatments can cause cognitive impairment. This means you are less able to concentrate, plan or remember information. The symptoms can affect your daily life in various ways.

Your treatment team may call this cognitive impairment, but you may also hear it called “chemo brain” or “brain fog”.

Cognitive impairment usually improves over time, but for some people it can continue, especially if the treatment causing it is ongoing.

It’s not known exactly what causes cognitive impairment during and after cancer treatment.

Although it’s commonly called “chemo brain”, cognitive impairment can affect anyone going through cancer treatment even if they do not have chemotherapy.

Some experts think chemotherapy may speed up the normal ageing process. There’s some evidence hormone therapies, such as letrozole, can also cause symptoms of cognitive impairment. The evidence for this is mixed and more research is needed to understand the causes.

Other factors may contribute to cognitive impairment, such as:

• Fatigue
• Difficulty sleeping
• Menopausal symptoms
• Poor diet

Symptoms vary from person to person and can come and go.

You may notice them during day-to-day activities or they may not be obvious.

Some common symptoms of cognitive impairment include:

• Short-term memory loss
• Finding it difficult to concentrate or think clearly
• Finding it difficult to do more than 1 thing at a time
• Being unable to put thoughts into action
• Being less organised than usual
• Having trouble finding the right words or finishing sentences
• Feeling tired (fatigue) or lacking energy

Talk to your treatment team if you have these symptoms. They can assess you and provide support to help manage and improve your symptoms.

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

However, there are some things you can do to help manage your symptoms:

• Keep a diary – this may help you notice patterns, for example it may be worse when you’re hungry or tired
• Write things down – use a calendar, your phone alarm or a notepad to write down reminders
• Plan ahead – meal plan for the week ahead and prepare for big events or busy days in advance
• Use a pill box organiser if you’re taking regular medications
• Focus on 1 task at a time
• Eat a healthy balanced diet and keep yourself hydrated
• Brain training – keep your brain active at times by using brain training games and apps
• Regular physical activity – focus on exercise you enjoy such as walking, swimming or yoga
• Mindfulness – many people find taking time out to practise mindfulness or relaxation techniques can help
• Use sleep apps like Calm, Headspace and Sleepio to help improve your sleep

It can help to talk your family and friends about cognitive impairment and how it’s affecting you. They may be able to offer support and practical help, such as food shopping and meal planning.

Lifestyle factors, such as difficulty sleeping or stress, can also make the symptoms of cognitive impairment worse. Talk to your treatment team about how to manage these.

Some people find different brands of treatments such as hormone therapies can make cognitive impairment better or worse. You could keep a record of the brand you’re prescribed and the symptoms you experience. You can ask your GP if they are able to prescribe the brand you feel suits you best. However, you may also need to check if a pharmacy has the brand in stock or would be willing to try to get it for you.

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

Cognitive impairment can make it difficult to carry out your usual role at work. This can lead to you feeling stressed, which can make the symptoms worse.

If you’re worried about work, or returning to work, speak to your employer about reasonable adjustments. These could be a temporary change to your work hours or more regular breaks.

Occupational health services might help employees who have cognitive impairment. Your manager or human resources team may be able to tell you about these and suggest other sources of support.

Working with Cancer offer support and advice for people affected by cancer. 

If you’re self-employed, you can call Macmillan Cancer Support on 0808 808 00 00 to find out what support is available. They also have information on self-employment and cancer.

Cognitive impairment can be difficult to cope with, and many people feel frustrated.

You can connect with other people experiencing cognitive impairment through our online forum.

You can also call our free helpline on 0808 800 6000 to speak to one of our specialist nurses.