Fatigue in Dementialand (aka Why the Dementia Brain is So Tired)

Today we are back to Q’s and A’s. Today’s question is from Carole…

My husband is very fatigued, and sleeps way more than he used to. There are no medication changes, and he is on the same medications he has been for years (low dose ramipril, Lipitor, and hydrochlorthiazide). If we go for a very short walk, he is “exhausted” and will complain of his leg muscles being sore. All labs are within a normal range. Does anyone know the cause of increased fatigue associated with dementia?


Dear Carole,

Because I have to do my due diligence, I’ll go through some things that can cause fatigue in someone with dementia–medications (and he might react to some medications differently as he progresses), sleep issues (it’s likely he’s not sleeping as well as he used to), poor nutrition (people with dementia sometimes crave less healthy food like sugary treats), and depression (which is not surprisingly common among those with dementia). Kudos to you for making sure those labs are in the normal range.

But you know what? Even if none of the above factors are in play, dementia makes people tired. In short, it is exhausting to have dementia.

We often look at people with dementia, and it seems like they’re not trying. Let me assure you they are actually working really hard to do things that us folks without dementia do quite effortlessly.

I’m going to give you an analogy here, and it’s a really awful one. I played several sports in high school. I looked pretty athletic. However, I was–and still am–a very slow sprinter. When we ran sprints in sports, I always got in trouble for not hustling. My coaches thought I wasn’t trying when I was running my heart out. I was just really slow. I’d look at my teammates, who were effortlessly running 100 yards in the time it took me to run 60. And it was frustrating as heck. I remember telling a basketball coach in high school, “I know I look fit and it seems like I should be able to run fast, but I’m trying my best and I’m just super slow.”

No, high school basketball and dementia are not the same. Yet we can all think of a time when we were putting a lot of effort into something that was difficult for us (but easy for others) and another person accused us of not trying. It’s maddening.

You probably see where I’m going here. People with dementia are often perceived as not trying when in fact they are working extremely hard. The dementia brain must work constantly to make sense of the world. It is struggling to interpret one’s environment in the way that the non-dementia brain might struggle to understand a calculus problem when one never took a calculus class.

And, Carole, when you mention a walk, I think of all the changing sights, smells, and sounds your husband’s brain must constantly interpret. An effortless chat (on your part) is probably quite challenging for him as he must filter all the stimuli he encounters to focus on your voice and interpret what you say. And that’s tiring.

I have a friend with dementia who told me she’d meet with friends that would say something like, “You don’t seem like you have dementia. You just seem normal.”

What they didn’t realize, she conveyed to me, was how hard her brain was working to carry on a “normal” conversation while they were together–and how tired she would be after their visit. The longer the visit lasted, the less likely she was able to be “normal.” Her brain just got too tired.

(Notice I put “normal” in quotes. I don’t like when we allude to people without dementia as normal and those with dementia as not normal. We’re all weird, anyway. It’s what I like about people.)

Mental energy is a precious resource for all of us, especially those with dementia, and mental energy isn’t independent of physical energy. Think about….When you are mentally exhausted from a long and stressful day at work, it’s hard to get yourself to the gym for a workout.

People with dementia often have high levels of anxiety. Here is the tricky thing about anxiety–being keyed up all the time makes you tired but makes it hard to sleep well. Then you end up exhausted but jittery and tense, which is an uncomfortable feeling that leads to more fatigue and more anxiety.

Sometimes my brain gets tired. Maybe I’ve been grading too long. Maybe I’ve been working on a tedious report for the university. Perhaps I’m looking at data for a research study. My brain, just like every brain, needs a break sometimes. And I can give it a break. In fact, I have to give my brain a break at some point or my productivity suffers.

It’s harder to give the dementia brain a break. I can stop doing something that is mentally strenuous and do something that is mindless. Unfortunately, for someone with dementia, it becomes harder to find something mindless. Even doing something seemingly simple (like watching TV, having a conversation, listening to the birds), isn’t a break for the advanced dementia brain. The person may feel an urge to sleep in an effort to protect their brain from being overwhelmed.

Carole, I hope that’s somewhat helpful. If you ask someone else, they might conceptualize the association between dementia and fatigue differently. My answer, really, is pretty simple.

Your husband is tired because having dementia is tiring.




11 thoughts on “Fatigue in Dementialand (aka Why the Dementia Brain is So Tired)

  1. I really appreciate this post. My husband tires so quickly. Like today. He rested all afternoon, then got up for dinner and after dinner stayed at the table watching tv and sipping his drink. At the end of a show he said I am ready for bed will you help me. Of course, I do every evening do I not? Yes he said. I mentioned it is not 9pm yet and he said but it is close and I am tired so off we went. We joked and laughed a bit and then was time to sleep.


  2. Thank you for explaining it so clearly. I have shared it on my blog so people can understand. I have dementia and I am 47. I get tired very quickly, although i tend to push myself, accept when I can’t. When walking, sometimes its like walking through treacle, when going to London, the next day i rest all day. I pace myself for this reason


  3. Thank you for putting into words what I am experiencing. It helps me understand the unexplainable. I was diagnosed 2 yrs ago at age 62. I am sharing this publicly in hopes that my family will better understand why I nap so much. It certainly helped me understand it better. Keep up the dialogue! Salute


  4. I just posted this to my Facebook page because it explains so well of what is happening when I tell people “I feel my brain going numb” or “starting to shutdown.” I do struggle to keep up with what is happening around me. I have a real need for a quiet room and often multiple naps. I am 56 years old and was diagnosed with Alzheimer’s a year ago. Thank you for the article!


  5. Thank you for explaining this my mom has thisand just recently she has been sleeping more and she would watch tv more it just didnt make sense until you shared this.
    Need to learn more loved this post


  6. Wow, thanks Elaine for all of this information! This all makes sense to me, and gives me a better understanding and more empathy for the fatigue that he suffers. Perspective taking goes a long way when we’re supporting someone with dementia.

    For my husband, his high level of anxiety combined with brain fatigue from trying to interpret his surroundings must be overwhelming for him. His preference these days for sitting and watching TV makes more sense to me. Not as stressful as trying to function in a “normal” environment.


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