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Thyroid Patients Share Their Brain Fog Moments

Thyroid Patients Share Their Brain Fog Moments

Brain fog is often described as ‘feelings of mental confusion or lack of mental clarity’. The phrase comes from the feeling of a fog that reduces your ability to think clearly. It can feel like a mental block. It can cause a person to become forgetful, detached, discouraged and even depressed as a knock on effect.

Brain fog is a common symptom of thyroid problems, particularly hypothyroidism and Hashimoto’s.

Thyroid hormone, particularly T3, has an important role in the health and optimal functioning of your brain, including: cognitive function, the ability to concentrate, mood, memory and attention span. This explains why we can experience symptoms such as brain fog. T3 interacts with brain receptors and makes the brain more sensitive to chemicals such as serotonin and norepinephrine, which affects your alertness, memory, mood and emotion.

These days, I hardly ever experience thyroid brain fog, but some of the things it has made me do in the past, are pretty funny. 

Using my house key to try and get through the front door, but it didn’t work. Then I realised I was trying to get in to a neighbour’s house.

Putting lipstick on my eyes.

Whilst in the bath, squeezing conditioner on to my hand then running it all over my face as if it’s face wash.

I also asked my thyroid community what things their thyroid brain fog had lead them to do in the past.

Rachel has Brain Fog

“Using a ticket machine that requires your car registration number to be entered. I went back to my car three times to check as I just couldn’t remember it. Might not seem too odd but I use this car park twice a week and have done for years. Had a bad thyroid day and my mind just went totally blank. So embarrassing.”

“I have a hard time with words and that’s something I never had a problem with until I got Hashimoto’s disease. I also walk into a room and forget what I was walking in there to get. I have a number of brain fog moments but unfortunately it’s so bad I can’t remember them all.”

Thyroid Brain Fog“I have tried to get into my car with my house keys, put some veggies on to boil with no water, made numerous cups of tea without boiling the kettle, put washing up liquid in the fridge and regularly can’t think of certain words when in a conversation.”

“I had a nursing final one morning and couldn’t shake the brain fog. Tried to go on the wrong interstate exit, couldn’t think straight, ran late. I had fog through the whole test and barely remember it.”

Thyroid Brain Fog

“The shower is the worst for me. I forget to: remove my socks, actually wash my hair, how to close the faucet and I thought there was something wrong with my eyes because I couldn’t see – a white fog was glossing over my eyes and it was getting worse. I started to panic and cry, turns out I forgot to remove my glasses and they were fogging up.”

“Just yesterday, I went to Walmart’s self checkout. I grabbed my bag and walked away. Then I thought, I didn’t grab my receipt. So I turned to go back, and the monitor lady was at the register trying to clear it out. I NEVER EVEN PAID!”

Thyroid Brain Fog

“I have my sister call my phone so I can find it. Then I find it and for a moment wonder who just called me!”

“Went to work one morning and forgot where I worked, drove around looking for a pay phone to call my husband and ask him where I worked. After I found one I forgot why I was calling.”

Related article: I Worry That Brain Fog Makes Me Look Incompetent at Work

Thyroid Brain Fog

“Putting the opened milk carton back into the cupboard instead of the fridge; doing a load of laundry without the detergent; I’d stop mid sentence to think of the word that should follow next.”

“Going to put the end of an incense stick in my mouth whilst lighting the other end and I don’t even smoke…”

Thyroid Brain Fog

“Staring at a simple email I need to respond to for 20 minutes and can’t formulate any kind of answer.”

“Forgetting words in the middle of a conversation and just going blank. Very frustrating for me and the folks around me.”

Thyroid Brain Fog

You can add your own in the comments section too. 

Read other posts in the ‘Thyroid Patients Explain’ format here

If you are on thyroid medication and still having issues with fatigue, brain fog and other hypothyroidism symptoms, you may not be optimally treated, or have other problems that require your attention. A properly treated thyroid condition should have no or very few symptoms. Of course, other illness, conditions and deficiencies can cause problems too, so explore them all if possible.

See also:

Book1Edition2CoverThe book Be Your Own Thyroid Advocate: When You’re Sick and Tired of Being Sick and Tiredwhich walks you through how to overcome thyroid symptoms and live well.

You can click on the hyperlinks in the above post to learn more and see references to information given.

About Author

Rachel Hill is the highly ranked and multi-award winning thyroid patient advocate, writer, speaker and author behind The Invisible Hypothyroidism. Her thyroid advocacy work includes writing articles, authoring books, producing her Thyroid Family email newsletters and speaking on podcasts and at events about the many aspects thyroid disease affects and how to overcome these. She is well-recognised as a crucial and influential contributor to the thyroid community and has a large social media presence. Her bestselling books include "Be Your Own Thyroid Advocate" and "You, Me and Hypothyroidism".


  • Jackie
    February 22, 2024 at 3:21 pm

    Hi, Rachel!

    Thank you for compiling these brain fog experiences. It helps people know that they’re not alone and for some that can be encouraging. Have you found that when you’re feeling stressed, you have less mental clarity and more incidences of brain fog?

  • Teresa S
    January 12, 2023 at 6:45 pm

    I’ve never read what others experience with brain fog is , I have many of peoples symptoms since having my thyroid removed. I’m 58. How would one know if it’s just part of aging or maybe onset of dementia or Alzheimer’s ?? Brain fog seems to mimic other illness’s

  • Ann
    November 8, 2021 at 5:47 pm

    These are humbling experiences. I can relate to forgetting the next word I would use, going to the basement and forgetting what I was there to do (daily), and leaving a measuring cup in flour I used in the freezer for a month. This sounds like me!

    • Layle
      July 14, 2022 at 11:05 pm

      I have issues like these. It is unacceptable in society and I have lost friends and family because of it. How do you maintain a job and social life? Im 20 and got sick before I had the chance to work. I need help finding a job I can function at with issues like these.

  • Sarah
    September 21, 2021 at 9:54 pm

    I completely forgot a colleagues name. I’ve worked there for over 4 years and I just had a complete blank. Forgetting words during conversations and forgetting what I’m doing 2 seconds after I’ve thought ‘I must do that’.

  • Sharon Baker
    September 21, 2021 at 9:29 pm

    I don’t have issues with my thyroid, but can relate to the brain fog. No where near as bad. I seriously feel horrible for you. It has to be very scary. I’m 62 and I know its age and being human, stressed, and other things. That’s why I retired early, to ward off such things if that’s possible.


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