Cognitive fatigue

We want you to be able to feel some sort of control over how you use your energy levels and how to best manage these.

You may have many questions regarding this such as:

  • What is cognitive fatigue?
  • How does cognitive fatigue impact on what I do?
  • What can I do to manage this?

Cognitive Fatigue can be defined simply as 'brain fog' and you may have seen it sometimes referred to in the cancer literature as 'chemo brain'. You do not necessarily have to have had chemotherapy to experience, as cognitive fatigue is common for anyone who has had a cancer episode.

It can impact on your day to day activities, and effect your confidence in your abilities to concentrate and remember things.

You may have difficulties with:

  • Problem solving
  • Following a programme on the television
  • Concentration and remembering things
  • Finding the right words to say when socialising
  • Forget what you were going to say or do

You may have one or more of the above difficulties. These can occur more frequently when you are tired. Try not to over worry about these symptoms as they are common.

The most important message here is that the vast majority of people who have had a cancer experience and associated treatments will at some point suffer with cognitive fatigue. It doesn’t mean you are losing the plot but rather you are unable to think straight because you are so tired.

Staying Calm

Staying calm is important and will help you control feelings of panic and embarrassment. If you find yourself unable to contribute for example to social situations, take time to breathe and try and relax.  Explain to people you are feeling really tired. It may be that when your fatigue levels are rising brain fog is an indicator that you need to slow down,  pace and restore yourself.

Planning Cognitive Activities

If you have an important discussion or administrative task to do try and plan a time when you feel your cognitive energy might be at its best level. For some this may be first thing in the morning but we are all individual so this may vary. An important meeting with an employer for example may need to be planned in this way if possible.


Do not feel guilty about taking time out to rest your mind. Distraction with something you enjoy doing and is relaxing can help. We are all different and for some, for example, this may mean sitting down with a warm drink and for others a short stroll in the fresh air. Get to know what relaxes and restores you and set some time aside each day to treat yourself to this protected time.

Practical Strategies

If brain fog is persistent consider making life easier by using some simple strategies. This could be using a calendar or diary to jot down things you want to remember and cross these off the to do list as you go along. Putting everyday items such as car keys in the same place each time you use them will also help preserve valuable energy and help reduce feelings of frustration when you are unable to find them.