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Understanding Chemo Brain

It's not just in your head!

Key points

  • Chemo brain is a real, multifaceted problem that can cause impairing and frustrating symptoms.
  • Evidence-based strategies to manage chemo brain exist, and, with practice, can help make these symptoms more manageable.
  • Taking care of your body, managing stress, challenging your brain, and staying organized can all help alleviate chemo brain.

"Chemo brain" has a bit of a complicated history. Although the symptoms of feeling foggy, forgetful, and distracted have been well-recognized among cancer survivors for decades, historically, it has been dismissed in the medical community. The thinking behind this reluctance to acknowledge chemo brain was rooted in an understanding that because many chemotherapy drugs don't cross the blood-brain barrier, the symptoms described by patients must be related to the stress of treatment. In recent years, however, there has been a greater understanding of multiple ways that cancer treatment may influence cognition.

What is chemo brain?

Chemo brain, also referred to as chemo fog, or treatment-related cognitive impairment, refers to cognitive changes after cancer treatment: Trouble with attention, concentration, working memory, and executive function. People with a cancer diagnosis describe feeling unusually disorganized, having trouble with multitasking, finding it challenging to remember details or to learn new things, and feeling like their thinking is sluggish. It is common, with most estimates suggesting that up to two-thirds of patients experience this problem1. While most can expect these symptoms to improve 9-12 months after finishing treatment, around 10-20 percent may have these symptoms even years after treatment completion1. "Chemo brain" is also a bit of a misnomer, as radiation, surgery, and hormonal treatments have also all been linked to these cognitive difficulties.

What causes chemo brain?

There is not any one cause for chemo brain. There are likely a number of factors that compound one another that influence these symptoms. There is some evidence that cancer itself can create a pro-inflammatory state that causes inflammatory cytokines to cross the blood-brain barrier, affecting the functioning of neurons.2 Other causes include damage produced by the treatments themselves that occur along with damage directed at cancer cells, including damage to white and gray matter in the brain, microvascular injury, DNA damage, and oxidative stress. Some cancer treatments can also cause treatable conditions such as anemia or nutritional deficiencies that contribute to these symptoms.

The severity of chemo brain is affected by many things, including psychosocial factors (age, education, level of support, anxiety, depression) and medical factors (hormone levels, disease site and stage, and type and length of treatment).

So, while chemo brain is experienced "in your head," there are numerous pathways in your body and environment that can influence your symptoms.

How to manage chemo brain

While there is no quick fix to completely eliminate symptoms of chemo brain, there are effective strategies borrowed from brain injury research that have been demonstrated to help manage cognitive impairment related to cancer treatment.

Good self-care

Your body has the best possible chance to recover from treatment when you're taking good care of it. We know that untreated pain or interrupted sleep can worsen chemo brain, so it's worth talking to your doctor about these issues if they haven't been managed well.

Regular exercise (making sure you're pacing, as I discussed in a previous post) can also help manage symptoms. There is evidence that cardiovascular exercise stimulates the growth of new neurons and improves connections between brain cells.3 It may also alleviate fatigue, which can contribute to chemo brain. A nutritious diet filled with antioxidants and maintaining a healthy weight may also minimize symptoms.


Attending to your emotional well-being is critical for managing chemo brain symptoms. We know that we tend not to think well when we are stressed. In fact, research suggests that the tasks of the prefrontal cortex (the part of our brains that helps with planning, organizing, self-regulation, and keeping up with tasks) are interrupted when our stress level is too high4. When those same processes are already strained due to the effects of treatment, it can become nearly impossible to function well when stress is added on top of it.

Practicing patience and self-compassion is essential, as a flustered mind tends to be a forgetful mind. You may also need to rethink how tasks are distributed in your household. It is easy to get overwhelmed and fall behind if you are overscheduled and inundated by tasks. If you have not been in the habit of prioritizing stress management, now is an excellent time to make that commitment to yourself.

Cognitive and organizational strategies

Research from the cognitive rehabilitation world has shed light on the benefit of organizational and novel learning for chemo brain. Our brains seem to recover faster when we experience new and challenging situations3, while organizational strategies can help compensate for chemo brain symptoms and help everyday tasks feel more manageable.

  • Exercise your brain: Activities like Sudoko, crosswords, word puzzles, and brain training games such as Lumosity and NeuroNation may help stimulate brain plasticity and encourage recovery3.
  • Verbal rehearsal: Talking to yourself as you're walking through a task or trying to remember something may help with distraction and memory retention.
  • Put commonly used objects in the same place, every time: It may seem simple, but identifying one location for the items you most often lose track of can save time and aggravation.
  • Use notebooks, note apps, calendars: If you haven't needed to write down tasks or appointments in the past, this can be an easy change to keep yourself on track.
  • Use a timer for tasks: You may not be able to focus as long as you have in the past. Instead of fighting it, plan around it by giving yourself a specific amount of time to focus on a task and then take a break. It can also help with redirecting your attention if you get distracted. If the timer hasn't gone off, it's a reminder to go back to the task at hand.
  • Focus on one task at a time: It's easy to make mistakes when you're bouncing from task to task. Focusing on one thing at time, perhaps using a timer as described above, makes it more likely you can follow a task from start to completion.
  • Outline steps: Prior to starting a task, it may help to write down the steps needed to complete it. It helps to organize the task, but can also be used as a reference if you get distracted. Crossing off steps as you go allows you to keep your place.
  • Reduce distractions: In the past, you may have been able to get things accomplished while there were multiple things happening at the same time, such as having a conversation with the television on. Staying focused is easier when you minimize background distractions.
  • Give yourself more time: It may take longer to accomplish tasks. Rather than getting surprised and frustrated by it, try to build in extra time so you can plan around it.

When to see a professional

Most people will start to see some improvement in chemo brain symptoms a couple of months after completing their treatment. If you still feel significantly impaired about a year after finishing treatment, or if you require ongoing treatment and are still struggling with these symptoms, it may be time to talk to a professional. If you've tried some of the techniques described above with no change, talk to your oncologist. They may refer you to a neurologist, a neuropsychologist, or a psychiatrist with some expertise in working with cognitive difficulties. They can help explore more options with you, which may include medications or a cognitive rehabilitation program.

Stay compassionate

Chemo brain is challenging and can result in significant frustration and negative self-talk. It's easy to get stuck in a loop of unhelpful thinking, such as "I used to be able to do this, why am I struggling now?," or "I shouldn't have to work so hard at this." Taking a compassionate, accepting approach provides opportunities for shifting from being stuck toward taking steps to adapt to these challenging symptoms.

To find a therapist near you, visit the Psychology Today Therapy Directory.


Meyer, F. (n.d.). Tips for managing chemobrain.…

Cheung, Y. T., Ng, T., Shwe, M., Ho, H. K., Foo, K. M., Cham, M. T., Lee, J. A., Fan, G., Tan, Y. P., Yong, W. S., Madhukumar, P., Loo, S. K., Ang, S. F., Wong, M., Chay, W. Y., Ooi, W. S., Dent, R. A., Yap, Y. S., Ng, R., & Chan, A. (2015). Association of proinflammatory cytokines and chemotherapy-associated cognitive impairment in breast cancer patients: a multi-centered, prospective, cohort study. Annals of oncology : official journal of the European Society for Medical Oncology, 26(7), 1446–1451.

Dietrich, J. (2019, November 20). Suffering from "chemo brain"? There's hope and many things you can do.…

Cibrian-Llanderal, T., & Hernandez-Baltazar, M. M. a. (2018). Stress and Cognition: Psychological Basis and Support Resources. In (Ed.), Health and Academic Achievement. IntechOpen.

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