Research has shown that 1 in 3 people who have had treatment for cancer experience declines in their thinking abilities. This is sometimes called “cancer-related brain fog”.

Some symptoms of cancer-related brain fog are having a hard time:

  • Focusing on a task for long
  • Finding the right word or the name of someone you know
  • Learning new information or skills
  • Recalling information that you know 
  • Multitasking and organizing daily tasks
  • Paying attention – losing your train of thought
  • Getting things done as quickly as you did before



The precise causes of cancer-related brain fog are poorly understood. Causes may be different for different people and may change over time. 


What you can do

There are currently no medical treatments for cancer-related brain fog. However, symptoms may be improved with changes in behaviour and adopting some methods to offset the effects of brain-fog. For more information read 'Cancer-Related Brain Fog' [PDF, opens in new window] »

If you are concerned about your symptoms, ask your oncologist (cancer doctor) or family doctor if there are any blood tests or brain imaging tests that can help rule out other causes such as thyroid, B12, sleep apnea, anxiety, depression etc.

Attend a class at Princess Margaret Cancer Centre called “What you can do about brain fog". See the schedule for the 'What You Can Do About Brain Fog' class. You can also ask your doctor about a referral to the Neurocognitive Clinic.


More information


* Acknowledgement - The Truth of It video series is a joint initiative of the Canadian Partnership Against Cancer and the Health Design Lab, part of the Li Ka Shing Knowledge Institute at St. Michael's Hospital in Toronto.


Last reviewed: 1/4/2018
Last modified: 11/1/2023 7:03 AM
Back to Top