What is chemo brain?

During cancer treatment, you may experience different side effects.

These can vary depending on the type of cancer you have, the treatment you are receiving and your individual circumstances. One side effect you may have heard of is chemo brain.

Chemo brain, also called chemo fog, is a term used to describe thinking and memory problems that can happen during or after chemotherapy treatment. The medical term for chemo brain is cancer-related-cognitive-impairment (CRCI).

What causes chemo brain?

The exact cause of chemo brain is not fully known. Research suggests that it may be linked to a combination of factors, including cancer treatment, the cancer itself, stress, fatigue, anxiety, depression and sleep problems.

How does chemo brain affect cancer patients?

Chemo brain may affect people in different ways. It can affect memory, concentration, processing speed and decision-making.

People experiencing chemo brain may notice:

Difficulty concentrating
Forgetfulness
Problems making decisions
Difficulty multitasking
Taking longer to finish things
Trouble remembering common words
Difficulty learning new things

How common is chemo brain and how long does it last?

Chemo brain is common during and after cancer treatment. For many people, symptoms improve over time, but some people continue to notice changes in memory or concentration for months or longer after treatment.

There is currently no established medicine specifically for chemo brain, but research is ongoing. Some strategies may help improve symptoms and make them easier to manage.

These may include:

Brain training activities
Memory aids such as checklists, reminders and routines
Gentle exercise
Mindfulness, relaxation or meditation

Coping with chemo brain

While chemo brain can be frustrating, it often improves with time. Stress and tiredness can contribute to memory and concentration problems, so try to get enough rest and build regular relaxation and exercise into your routine.

Be open with your friends, loved ones and whānau about your symptoms and let them know how they can support you.

Tell your doctor or care team if memory or concentration problems are affecting your daily life.

Specialised allied health professionals, such as psychologists and occupational therapists, may also help you and whānau cope with treatment side effects.

References

1. National Cancer Institute. (2023). Memory or concentration problems and cancer treatment. Retrieved March 11, 2026, from https://www.cancer.gov/about-cancer/treatment/side-effects/memory
2. American Cancer Society. (n.d.). Changes in memory, thinking, and focus (chemo brain). Retrieved March 11, 2026, from https://www.cancer.org/cancer/managing-cancer/side-effects/changes-in-mood-or-thinking/chemo-brain.html
3. Breast Cancer Foundation NZ. (n.d.). Coping with long term side effects of treatment. Retrieved March 11, 2026, from https://www.breastcancerfoundation.org.nz/support/moving-forward-after-treatment/coping-with-long-term-side-effects-of-treatment
4. Yang, Y., Lin, J., Li, Y., Luo, J., Wang, L., Zhang, X., & Zhang, Y. (2024). Cancer-related cognitive impairment: Updates to treatment, prevention, and risk factor management. ESMO Open, 9(5). Retrieved March 11, 2026, from https://pubmed.ncbi.nlm.nih.gov/39260437/
5. Nakamura, Z. M., Deal, A. M., Nyrop, K. A., et al. (2024). Impact of cognitive rehabilitation on cancer-related cognitive impairment in cancer survivors: A systematic review. Cancer Nursing. Retrieved March 11, 2026, from https://pubmed.ncbi.nlm.nih.gov/39048409/
6. Rick, O., Bokemeyer, C., Seifart, U., et al. (2024). Cancer-related cognitive dysfunction: A narrative review from diagnosis to treatment. Journal of Cancer Research and Clinical Oncology. Retrieved March 11, 2026, from https://pubmed.ncbi.nlm.nih.gov/38471462/

Disclaimer

Content found on the Icon Cancer Centre website is for informational purposes only and should not be considered medical advice. It is not a substitute for consultation with a qualified medical practitioner. For personalised medical guidance, please consult with your GP or another qualified healthcare provider.

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