If you are undergoing Chemotherapy and experience episodes of memory loss, or difficulty in focusing or simply feel your brain is all fogged up, you are not imagining these symptoms. Sometimes people with cancer worry about, joke about, or become frustrated by what they describe as mental cloudiness or changes they might notice during, and after cancer treatment. This cloudiness or mental change is commonly referred to as “chemo brain”.

Mayo Clinic defines this phenomenon as “a common term used to describe thinking and memory problems that can occur during and after cancer treatment.”

What is chemo brain?

Chemo brain can also be called chemo fog, cancer-related cognitive impairment, or cognitive dysfunction. Even though its exact cause is not known, it can happen at any time when you have cancer and not limited to chemotherapy for breast cancer.

Chemo brain is most commonly connected with chemotherapy, but other treatments, such as hormone therapy, radiation, and surgery may be associated with it also.

Here are some examples of what patients with chemo brain may experience:

Forgetting things that they usually have no trouble remembering (memory lapses)

Trouble concentrating (can’t focus on what one is doing, have a short attention span, may easily “space out”)

Trouble remembering details like names, dates, and sometimes larger events

Trouble learning new things

Taking longer to finish things (disorganised, slower thinking and processing)

Trouble remembering common words (unable to find the right words to finish a sentence)

For most people, these mental changes only last a short time. Others can have long-term or delayed mental changes.

Certain circumstances can increase the risk of developing chemo brain or worsening brain function problems.

These include:

The cancer itself, for example brain tumors

Other conditions or illnesses, such as diabetes or high blood pressure

Emotional distress such as depression or anxiety


Hormone changes or hormone treatments

Nutritional deficiencies

Using alcohol or other substances that can change your mental state

Most of these cause short-term problems, and get better as the underlying problem is treated or goes away. Others can lead to long-lasting brain problems unless the cause is treated.

Treatment of chemo brain

Treatments for chemo brain may include:

Cognitive rehabilitation: This might be part of a cancer rehabilitation programme. It includes activities to improve brain function such as learning how the brain works and ways to take in new information and performing new tasks; doing some activities over and over that become harder with time; and using tools to help stay organised such as planners or diaries.

Exercise: Exercise can improve your thinking and ability to focus. Activities such as gardening, caring for pets, or walking, can help improve your attention and concentration levels.

Meditation: Meditation and mindfulness exercises can help improve brain function by increasing your focus and awareness.

Consult with your cancer care team about these treatment suggestions and other options they may recommend to help you cope with any cognitive problems.

Day-to-day coping with chemo brain

Track your memory problems.

Keep a diary of when you notice problems and what’s going on at the time. Monitoring medications taken, time of day, and the situation you’re in might help you figure out what affects your memory. Keeping track of when the problems are most noticeable can also help you cope. You will know to avoid planning important conversations or appointments during those times. This record will also be useful when you talk with your doctor about these problems.

Try not to focus on how much these symptoms bother you.

Accepting the problem will help you deal with it. As many patients have noted, being able to laugh about things you can’t control can help you cope. And remember, you probably notice your problems much more than others do.

Ask for help when you need it. Friends and loved ones can help with daily tasks to cut down on distractions and help you save mental energy. Finding and getting support is important. Let them know what you are going through. You may feel relieved once you tell people about the problems you sometimes have with your memory or thinking.

Talk with your doctor or cancer care team

If this mental fogginess causes anxiety at work or school, or interfere with your usual activities, talk with your doctor to try and pinpoint what’s causing your brain fog and what can be done about it.

For instance, are they worse in the morning or evening?

Do you have more trouble when you are hungry or tired?

Does it help to nap, walk, or have a snack?

Your doctor will want to know when the problems started and how they affect your daily life and may refer to an occupational therapist or a neuropsychologist.

Can chemo brain be prevented?

Even though this might be a change that’s not easy to see, like other changes such as hair loss or skin changes, chemo brain is a side effect you can learn to manage with the right support and awareness. Most importantly, do not judge yourself harshly when this happens and recognise, this is not entirely within your control.