An elaboration on Chemo Brain or Brain Fog

Hi everyone, before I start I wish you the very best for your own cancer journeys.

I wish to open a dialogue to expand on people’s experiences on Chemo Brain, also known as Brain Fog. My Nurse Specialist at hospital was the first person to mention this term to me.

I am currently going through Acute Myeloid Leukaemia treatment, and I thought I would start to document some of the wondrous oddities I have encountered that I attribute to Chemo Brain. I am interested to hear other’s experiences and how they explain them, and hope this becomes a useful resource to help people realise “it’s not just me getting this”.

I am no medical person (background is IT), and there are no medical instructions or professional opinion in what follows here. From what I read elsewhere on this forum both C.R. UK and Macmillan have articles about this, and I’m going to put aside some time to read them soon.

My simple view of Chemo brain first – the cumulative effects on my brain’s workings due to chemotherapy, other medication and just the whole thought-overload surrounding cancer diagnosis and what is coming next regarding that.


Thinking through treacle
I am used to thinking of solutions fast, “spinning multiple plates”, collaborating and arranging third-party engineers, a whole heap of “thinky” stuff.

During my treatment, I have had moments where when looking to apply ‘intelligence’ to figure something out … it just seems slower. I could liken it to being in a position of hearing the Jeopardy thinking-time music and being unable to think of the response to the host’s clues.

I’ve had to rearrange appointments, problem-solve, and it is great I can still do that. Just afterwards sometimes the brain almost needs to sit quietly as if it has run a mile (thought a mile?).

Being kind to myself and laughing at the oddness of it helps.


Single Mindedness
I’ve got a bit nervous of being messed-up during the ‘pill zone’ which has been part of my life for the last x months, in case I take the wrong one or two of the same that I shouldn’t etc. Creating a spreadsheet with times and tick boxes has helped this.

However if someone starts asking questions when I am taking say my morning ‘roster’ of pills, I get very grumbly and can get a bit abrupt in saying “not now”.

Maybe this is a thing spurred on from the protected meal-times in the hospital where unless something important was needed they left you to eat first and finish before checks and questions happen. If I have sat down to eat and start being questioned by family…. again that is very much a “not now” time. (With silent grumbling).

I am probably handling it less abruptly than I think, I just note that the mind is unwilling to process other things during those times. Also despite some family wanting to ask about future events, I don’t want to focus that far ahead – now and the very short-term future is where I am comfortable at the moment.

And honestly … this is not all a bad reaction. It actually feels empowering. Maybe something I should have been doing more before all this started.


Lack of focus
And then as a polar opposite to the above… Normally I learn reasonably fast. Not a photographic recall, but if it’s useful to me like a new system at work or learning German for a holiday, I can apply myself.

I wanted to start learning Japanese and thought I slow-time do it whilst in hospital. No pressure, no targets. Use an online flash-card tool. I know it’s going to be a big task to just get the basic so I’ll just chip away at it.

Just as well. Discounting the days where the intensive chemo made me want to hibernate or I’ve been busy, I just haven’t had the same drive to learn. I’m not even blaming the slight anaemia because I could just sit down and do the learning.

It has also taken weeks to write this, unusual for me.


Words on the tip of my tongue
I admit at times this has caused me concern until I learned to be a bit more kinder to myself. I’m not normally at a loss for words! No problems discussing things about my medical situation, so it’s clear my brain has prioritised that.

Sometimes metaphors and words just don’t flow out. This made me worried when I started a relationship a few months ago. There have been moments were I’m trying to say something important to her and key words don’t appear, or even more “hilariously” the wrong ones come out. Thankfully she is considerate and understanding (and we laugh about it later).


Patience levels can be all over the place
I am normally very patient. My career has involved staying calm and working on technical issues through multiple failed attempts to fix them.

This year is an extreme exercise in patience. And if waiting for emails etc regarding my treatment, I can accept my calm levels can be tested. And yet sometimes I am the calmest person in the room as close family fret over something regarding my health.

I’ve lost patience with myself over a disorganised cooking-lunch attempt when I got my timings wrong, and made a mess. Looking back I am now laughing because some of it was pretty funny, and I am glad I can still laugh at myself.

I’m getting better at accepting my patience is going to wildly vary due to my treatment. Just close your ears when I try to make playlists in iTunes……


Brain fatigue
Many jobs mentally tax us. IT is one, where at the end of the day flowery language and problem-solving may be absent from my capabilities.

I notice I am mentally exhausted by evening without the benefit of actually working. Even if the day is relatively free of calls or appointments. Maybe this is partly due to me having to consider more decisions that where normal before, such as what I can eat if I am neutropenic or how much I want to risk shopping when my immune system is slightly compromised and it gets closer to busy Christmas times.

Trying to schedule things to suit you is best for this. Do admin stuff during the day and not in the evening. Stagger tasks – do a bit further over some days than mash it all into one. (A three-hour session to fill in a large form and get it scanned was not one of my best decisions).

Side-note – anyone who believes you can get a lot of rest whilst in hospital clearly hasn’t experienced the 4-hour observations checks, the 2am temperature check, the lack of privacy, the calls to family who ask you questions you don’t have answers for. All that and you still have the actual drugs, chemo, daily blood tests and transfusions. I appreciate and am very glad for the level of care and attention (the reason I am here now is because of it), I just have to acknowledge it mentally flattens you.


@Catwithahat interesting breakdown, I have Polycythaemia vera (PV), and most of that applies without any drugs, just thick blood restricting blood oxygen to the muscles, including that big one hiding inside the cranium :wink:
Also depression and anxiety are also side effects, so a fun time, but it is OK, because it is a “good cancer”, who thought that statement up needs a NICE review.
Good luck in dealing with this all and dancing with your condition


Firstly @Catwithahat I’d like to wish you all the very best with your Acute myeloid leukaemia (AML) treatment. Brain fog where do I start? I didn’t notice it whilst I was undergoing my Acute myeloid leukaemia (AML) treatment a couple of years back but that may be because even though I was in isolation most of the time something was always happening. I started noticing “I had changed” 7 months after when I hit remission. Maybe before this I was mainly concentrating on my recovery. As I started to get my life slowly back I realised my cognitive skills were not as good as previously. Examples including stopping mid sentence as I’ve forgotten what I was saying, making a list on a list on a list, can’t recall names, getting tired quickly if too much brain power is used, cannot abide stress it really tires me. In a nutshell I’ve simplified my life somewhat but I’ve also accepted my circumstances and the way I am now. I actually said to someone the other day I’d never be able to do my former job - operations manager of a logistics company. I have also done some research into Acute myeloid leukaemia (AML) brain fog on the internet to prove to myself I haven’t lost my marbles :laughing: I know my daughter has struggled a bit with my decline but I’m happy as anything and sometimes it’s a good excuse to avoid things! Some days fine some days not quite as. I’m just exceptionally lucky to have been treated so well and so quickly. I hope this hasn’t sounded too negative as that’s not my intention. Take good care of yourself and keep posting


Wow, @Catwithahat I think that is the longest thread by one person I have ever read.
It was fascinating, thanks so much for taking the time to write it.
I have Chronic lymphocytic leukaemia (CLL) and always been on watch and wait so I cannot attribute my memory lapses to treatment.
However personally I do blame it on my age, I am now 73yrs old.
I do forget names sometimes, wonder why I walk into a room etc. but as you say I laugh it off.
Yes, as @Suenew1967 says I need to look after myself as I do not deal with stress well.
I also need to eat, drink and sleep well and keep my life as simple as possible.
Thanks for starting this thread and I await others musings.
Yes, it is so hard to get a good rest in hospital.
Be kind to yourself and my husband would be very impressed that you also have spreadsheets with your tablets on.


@Suenew1967 Great, you have given Yodel a whole new raft of excuses :smile: Or you could work for them and still be an improvement lol


@clickinhistory haha brilliant! Thankfully it wasn’t them that I worked for! :blush:


@Suenew1967 @clickinhistory @Catwithahat @Erica
Brain Fog,Chemo Brain.
When I had my treatment in 2008 this was not really recognised, maybe in the States.
On recovery I realised I could not retain people’s names but I could still remember faces. I could recall names if I had reason to write them down, I could tie the two together then & fix it.
I still get part way through telling a tale & forget where I was going with it.
Words are there one minute but when I try to say them they’ve disappeared.
I’m 15yrs older now, things have got better but if I’m tired or stressed they regress.
But I’m still here to tell the tale & experience life.


Thank you @Corfu80 , and I am very glad you are still here to tell the tale.


Thanks @clickinhistory @Suenew1967 @Erica @Corfu80

My girlfriend bought me some reusable in-ear noise buds. (Loops, although other brands are available :slight_smile: ). They really help cut out the equipment noise and outside call alarms, and are comfier than the disposable ear plugs you get in hospitals.

@Suenew1967 – not negative at all, and thank you for relating your experience. I’m not a fan of the term “new normal” however I realise there is a chance I won’t be going back to the same me in terms of what I can do at work. I also expect there may be some frustration on my part as I come to accept that when I actually face working again. Working to the same level doesn’t feel as important now.

@Erica – then your husband will also be intrigued to hear I used spreadsheets to lay out the facts for my transplant. I tried to break down all the worries I had to try one-by-one to answer them or discount them. Serious mental overload with all the different elements so was the only way I could approach them.

And @clickinhistory has kindly alluded to my next item to discuss…


Anxiety returns
When I was in late teens I had a lot of anxiety. And the focus we have going through cancer on hygiene definitely has brought back a bit of cleanliness over-focus I had. (Admittedly 2020 did that too).

I was… disappointed to see that during earlier treatment this year I was getting levels of anxiety that were like from back in my past, stuff I thought I had moved on from.

I’m in hospital now, and I see it raising a bit again. Given one of the chemo drugs has “mood swings” as a side effect, and I’ve been on intensive chemo for the last 5 days, I am not surprised.

It’s like a thought overload. My life coach described it as like a dog chasing its tail. It can be insidious how it starts, seems so small before suddenly it is very “noisy”. I then realise I have been pacing the room nervously, my muscles tight like it is a fight or flight response.

Taking time for a bit of grounding helps. An amount of chill-out music is also good. And sharing it with the nurses is a load off my mind. Sometimes sharing it with them is easier than with close family.

Have I noticed it when out of hospital? Slightly. Mostly tied to just wanting to get things like appointments done, drugs arranged, and shopping finished promptly. Or when meeting travel arrangements to then get taxi to hospital etc.

Unrelated note. When I take over the world (it’s in my list of goals :wink:), one law I will pass is whenever someone is diagnosed with a medical condition like Acute myeloid leukaemia (AML), Chronic lymphocytic leukaemia (CLL), Polycythaemia vera (PV) etc, they get appointed a personal assistant (state funded) to take care of the organisation and liaison steps for the treatment. I’m convinced a lot of anxiety and tiredness comes from this necessary busy-work, and chemo-brain isn’t a useful aid to that. (Apart from helping discount what is really not worth spending my time on).


@Catwithahat :wink:

Hey there @Catwithahat, really sorry to hear you’re living with Acute myeloid leukaemia (AML), fatigue and chemo brain. I have a different blood cancer, Polycythaemia vera (PV), but I know the fatigued foggy thinking only too well. It was my worst side effect after I started treatment as I had no symptoms before starting chemotherapy and thus could gauge what changes had occurred from taking daily hydroxyurea.

My fatigue was so bad that it also contributed a lot to affecting my moods and increasing anxiety, so I did some reading to find out if I was stuck with it or if there were ways to manage it better or preferably undo it altogether. This research was so helpful to me and continues to be. It basically states that up to 85 % of us survivors will experience cancer-related fatigue (CRF), and that “[o]f the interventions available for CRF, exercise-based interventions are the most promising and are recommended as first-line treatment for CRF.” The meta-analysis linked to above states that doing exercise such as yoga, tai chi, and qigong help best to reduce the symptoms of CRF.

Personally, I have found doing yoga a few times a week has helped a lot during the worst of my fatigue. It seems so counterintuitive that exercising will give more energy, but it really does! I’m a big hiker and just couldn’t get out into the hills at first after diagnosis as planning routes, or how to get to them, or even dragging myself out of bed at all felt so exhausting. Thanks, chemo brain. After getting back into yoga I noticed my energy did improve, as did my clarity of thinking.

Resting when a bout of fatigue comes on helps me too, otherwise my thinking can stall and it’s like I’m glitching. Eating smaller meals and foods that are easier to digest means less energy spent with food coma fatigue. Avoiding stressful scenarios when I’m most fatigued saves energy. I also make sure to get morning daylight into my eyes as it helps regulate my circadian rhythm and thus sleep better at more regular times of the night which doesn’t make me so tired the day after. All anecdotal, of course, but I used myself as a test subject and this stuff helps.

Anyway, hope that research helps you. I also hope your symptoms improve and your brain becomes less foggy!


Ha and yes please to a personal assistant! My husband probably feels like he is mine already, but we can live in hope!