Chemo brain is the common term used to describe the cognitive decline you may experience before, during, and/or after cancer treatment, even if you have not been treated with chemotherapy. This mental “fog,” as it is often described, is a side-effect that is marked by a lack of focus, the inability to concentrate, and trouble processing or remembering information. 


Chemo brain can also be referred to as cognitive dysfunction, cancer-related cognitive impairment, cancer-therapy associated cognitive change, or post-chemotherapy cognitive impairment. 

Some cancer patients only experience chemo brain for a short time, while others experience it for years. 

Researchers are working to find answers to the many questions regarding the memory changes that cancer patients who receive chemotherapy experience. While there is still much to learn, it’s clear that chemo brain can be a frustrating and debilitating side effect of cancer and its treatments.

Signs and Symptoms of Chemo Brain

Below are some examples of what patients call chemo brain: 

  • Difficulty concentrating, focusing or paying attention
  • Forgetfulness or memory lapses
  • Being unusually disorganized
  • Inability to multitask (do more than one thing at a time) 
  • Disorientation or extreme confusion
  • Trouble recalling or remembering details such as names, dates, and common words

The severity can range greatly. Some patients notice significant changes, while other cancer patients only experience subtle mental changes. And others don’t notice them at all. In many cases, patients don’t bring it to the attention of their cancer care team until these changes begin affecting their everyday life. 

Causes of Chemo Brain

The exact cause of chemo brain is unclear. Some cancer patients, who have never had chemotherapy, experience these symptoms. Because of this, it has been suggested that it could be a combination of factors including:  

  • Cancer treatment, such as chemotherapy, radiation therapy, hormone therapy, or targeted therapy
  • The cancer itself (particularly brain cancer)
  • Surgery and the anesthesia used during surgery
  • Medications, such as antibiotics, antidepressants, heart medications, anti-nausea medications, or pain medications 
  • Anemia (low red blood cell counts) 
  • Poor nutrition 
  • Infection
  • Sleep problems 
  • Fatigue
  • Age at the time of diagnosis
  • Stress and other emotions such as anxiety and depression, that often occur with a cancer diagnosis and treatments 
  • Other illnesses, such as high blood pressure and diabetes

11 Ways to Manage Chemo Brain

There are many things you can do to help sharpen your mind and manage chemo brain. Here are some suggestions to help you cope: 

  1. Keep track of your schedule and create reminders on a planner, computer, or smartphone. 
  2. Create a handy list, written or digital, that includes information such as phone numbers, addresses, meeting notes, and even movies or books you’re interested in. 
  3. Establish a structured routine by blocking off certain amounts of time to accomplish specific tasks. Time blocking is a simple, yet powerful technique that can increase motivation, improve focus, boost efficiency, and reduce stress.  
  4. Focus on completing one task at a time and avoid distractions. 
  5. Get enough rest and sleep.
  6. Exercise regularly, but only if you are able. Light to moderate activity is good for the body and the mind, even during cancer treatment, if approved by your oncologist. 
  7. Eat nutritious foods, especially a lot of vegetables, such as broccoli, beets, celery, and dark leafy greens, which are linked to boosting brain power as you age. 
  8. Track your memory problems, including when they happen as well as what’s going on at the time they occur (medications that you’ve taken, time of day, situation, etc). Doing this can help your doctor narrow down what specifically may be affecting your memory. Ask for help when you need it. Tell your friends and loved ones when you experience symptoms of chemo brain, so they can give support and help with daily tasks that might drain your mental energy. 

    In cases where cognitive problems are long-term, your doctor may prescribe other methods to help manage them. These may include: 
  9. Medications, including stimulants, cognition-enhancing drugs, antidepressants, and drugs that block how narcotics work, such as morphine
  10. Cognitive rehabilitation and cognitive training, which can help improve cognitive skills and coping abilities
  11. Occupational therapy and vocational rehabilitation to help patients handle job-related skills and the activities of daily living 

When to Talk With Your Oncologist 

Talk with your oncologist if you experience any symptoms of chemo brain. He or she will want to know when the problems started and how they affect your daily life, so it is important to keep track of each time you notice problems. 

Some questions you might want to ask your doctor could include: 

  • What is causing my chemo brain?
  • What do you recommend I do to improve my memory? Or my ability to focus?
  • How long should I expect my symptoms to last? Is there a treatment for my symptoms? 
  • Should I participate in any type of therapy that could help me with this? 
  • Is there a specific type of doctor who can help me with this? Can you recommend one? 

Keep track of the important facts you discuss with your doctor. Consider taking a friend or family member with you so they can help take notes and review them with you later on. 

In addition to talking with your cancer care team, you may want to share what you’re feeling with friends and family. Being able to talk with someone you care about and trust may provide you with some much-needed relief.