Mental fatigue, but no physical fatigue: Hi everyone... - Headway

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Mental fatigue, but no physical fatigue


Hi everyone,

Just trying to work out how common this is — does anyone experience mental fatigue, but not physical fatigue? By mental fatigue I mean you feel like you're slower to process things, memory and concentration might be affected. But you don't feel physically tired, e.g. you can exercise regularly and don't need to sleep more than average?

14 Replies

Yes a very common problem that effects people with a brain injury. Especially if it's the frontal lobes that have been damaged. What you are describing are executive function problems and the cognitive fatigue is because your brain is having to work considerably harder with executive functions.

Yip! What she said 😁sorry I have frontal lobe damage and executive dysfunction as well!!

I have a frontal brain injury as well as get easily overwhelmed and cognitively fatigued.

Yep like strawberry has said very common bi symptom. Even trying to conserve energy may have little effect.

Bi has a big impact on cognitive function making simple tasks harder to perform and making your brain work harder to achieve them.

Small rests or " chill outs" may improve your fatigue. You may not need to sleep just relax your brain. You may find you dip throughout the day making tasks harder to perform. Experiment with rest times to find what works for you.


This actually describes the man who runs BI group I go to and yea his frontal lobe was injured. He does loads of physical challenges and is fine. Actually not seen him after them but with amount he does I assume he’s fine and after a 9 mile hill walk last month he was fine tho did get bit tired towards end of journey back totally understandable. Yet have fun days out slow easy walk or bowling and he seems more tired probably cos of the planning and organising everything.

Frontal Lobe here and I struggle to know the difference now, although if I get to the Health Center exercise can help.

I can remember saying "I can't tell the difference" at a TBI rehab run group for CFS and even there people gave me a funny look.

Yup 100%, my ex wife couldn’t understand it but it’s real. I returned to work for a further 2 years after I had mine and found that my brain went into sleep mode my midday.

The last 6 months after I raised a grievance against my company I negotiated an hour earlier start and a 2 hour lunch break so I could nip home and have a nap. It meant I was more alert and productive in the afternoon.

As has previously been stated, try and establish common times that you get cognitively fatigued and plan short rest times. Good luck

I survived a TBI four years ago, walked the Pennine Way a couple of years ago. I restarted an insurance business 1 year ago and to start with it was a challenge. Pleased to say after a year of exercising my brain it has improved more than I expected it to. I have a claim meeting with four other people at 9 in the morning, mile from me, so I’ll be up at 6:30.

Personally i’m convinced that exercise is as important for your brain as it is for physical activities.

My. Brain concern is in the back, burst AVM in my cerebellum. I get extremely fatigued mentally, sometimes it's in the eye area, I guess coz they have to work hard and there so many tiny muscles in play. It seems it don't matter where the issue is, the outcome of fatigue is the same. I don't seem to get physically tired. I often say to my parents that I'm mentally tired but not physically. I may have not even done much. That's my experience any way. Jo

Thanks for everyone's replies. It's actually my partner who's suffered the BI. He gets fatigued easily at work (he's reduced his hours twice now to try to help), and we think maybe by things like reading or using a computer. Not certain about the last two as we are still trying to figure out all his triggers - sometimes the fatigue just seems to turn up, and we have to think hard about what he could have done to bring it on. It makes it more difficult to work it out because he doesn't seem to be affected by everything you would expect, e.g. he's fine with cooking.

He hasn't really had any rehabilitation yet, even though his accident was over a year ago. I think he will be working with a neuropsychologist soon. If it's executive function causing his fatigue, is this something rehab can target?

sealiphone in reply to Onedge93

Re-hab should identify which particular function(s) are now impaired and whilst this will give some idea of the triggers, I found it still took another 3 years to get a handle on it.

I think one difficulty, for me, in spotting the triggers is that my memory about the start of the onset is particularly vague.

I'd be careful with reading and looking at screens, I find both these tire me. I had my BI 4 years ago, and am only now really working out what tires me most, noisy parties are hard, I can hear OK, but its seperating the voice of the person I am talking to from the surrounding racket, that I find hard, and after 2 hours or so, my brain feels like a child's mechanical toy, slowly winding down, my balance becomes dodgy and I can't find words, so my husband has to scoop me up and drive me home, once in the quiet of the car, the relief is measurable! The following day is a write off, but now I am planning for that, which makes things easier. Physically my energy is fine, its just the mental fatigue, and you just have to work out what affects you the worst.

yes, 12 years in I've recovered well apart from the dreaded fatigue, once that kicks in BAM that's it, I can't speak, I cry, I get confused, words are just a ummm ummm. Some days are good some days are bad.

Yes- I have been running more since my concussion at start of March and now do 10k frequently. My heart rate is low and I generally feel very fit. But if I spend more than an hour or so reading I feel really headachey and nauseous and need to sleep. I wake up in the morning feeling I’ve had enough sleep so I think it’s the visual activity that is causing the tiredness.

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