My Personal Experiences

When Thyroid Disease Changes Your Personality

Developing a chronic illness or being diagnosed with one, such as Hashimoto’s or hypothyroidism, often changes your life in both obvious and not so obvious ways.

Areas it Touches

Depending on the level of severity that the person experiences, they may see changes in their personal life as they have less energy than they used to and struggle to keep on top of housework, for example.

They may see changes to work, as they put into place adaptations to make working with their health condition easier.

And changes in relationships often happen too, as some friends inevitably drop off the radar when you’re less able to make social events or they become less interested in you because you’re ‘sick’, and they don’t know what to say to you.

A Change in Personality

But one change that perhaps isn’t noted very often is the way in which the diagnosis or development of a health condition can lead to the change in your personality.

Since developing Hashimoto’s, Hypothyroidism and more, I know my personality has changed. It’s a realisation I’ve only come to more recently, despite holding these diagnoses for years now.

The way in which having hypothyroidism, a condition resulting from low thyroid hormone levels, has given me fatigue, brain fog and poor stamina to name just a few key symptoms, has definitely taken me from the bright, switched on, chatty, active and full of life Rachel, to a ditsy, sometimes absent-minded, reserved individual who may even be perceived as lazy.

Before becoming very ill, before my diagnoses, I was active – taking part in dance lessons, badminton sessions, hours of walking and running every week. I was far from lazy.

Before the thyroid condition, I was a quick learner; a sponge soaking up everything and anything and perceived as intelligent. I was always top of the class or in the top few.

My Worries 

However, I worry these days that work colleagues and even some friends think of me as ditsy, lazy, unintelligent and uninterested in conversations or meetings, when I struggle to contribute. When the truth is that my brain sometimes lags behind everyone else’s and it’s only ten minutes later that I have something to add to the conversation that my brain has now processed, but has equally passed in the present!

At the worst points of having hypothyroidism, I have gone from being very active to not being able to climb the stairs unaided. I’ve gone from quick thinking and great ideas to yawning deeply and looking blankly at someone as they ask me a question.

But, however big the negative changes to my personality may be, the positive changes are even bigger. And better.

Positive Changes To My Personality and Life 

Through learning to advocate for my own health and feeling empowered by that responsibility, I have become more confident.

I am more confident in advocating for my own healthcare (and subsequently, other peoples’), yes, but also more confident all-round.

I speak up for myself these days. I worry less about what other people think about me because I’m more self-assured. I am confident in my own abilities to do whatever the heck I want to because I have proven time and time again that I can do it.

I can slot a piece of the big thyroid jigsaw back in to place and make a step forward in terms of my health (e.g. with a thyroid medication change) but I can also write an article for a website and receive praise. I’ve even written a book.

Without my diagnoses, neither of these would be possible. My personality would never have changed in this way if it wasn’t for the thyroid condition existing. Sure, I always loved writing, but I never had a niche or topic to get passionate about. My diagnoses gave me that. It gives me a lot of what I’m passionate about and thankful for today.

Feeling More Appreciative 

I am also more appreciative. When you don’t always know if you’re going to wake up feeling your best or worst, you learn to savour the good health days. I am more appreciative of the simple ability to walk on the days that I can, because I know that flare-ups in my condition can come out of the blue, sometimes.

I appreciate the smaller and simpler things in life. I also appreciate the things I know my peers won’t until they’re a bit older.

I appreciate the value of real nutrition because of how everything I eat and drink either helping or hindering my health. I appreciate slowing down and I don’t need to be out partying every weekend. I appreciate calm dinners with friends. I appreciate having enough energy to change the bed sheets. I am much more aware of my blessings.

And the other major way my personality has changed with the thyroid diagnoses is by becoming more understanding.

By having my own world turned upside down, I developed empathy for others going through difficult times and trying to keep their head above water. I’ve always been a sympathetic character, but I could suddenly really put myself in another’s shoes and found a new sense of really feeling for them.

You see, although my health conditions can negatively affect my personality in some ways, the positive ways in which it has changed it far outweigh them.

And the nature of my conditions mean that they can get better and then sometimes get worse again. Flare ups, good days and bad days. Good health and not-so-good health. It’s a bit of a roller-coaster if I’m honest! And I’m not always able to see the next drop or pre-empt it.

How My Health is Now 

Right now, I’m thrilled to be in a very good place with my health, as it is well managed at the moment.

So right now, I feel quite clear headed and on top of my game. But that foggy minded, ditsy and sleepier Rachel can and probably will make an appearance again one day. In fact, it could be tomorrow, as flare ups don’t always mean weeks or months of heightened symptoms, but can even mean 24-hours.

And when those personality alterations rear their head again, I will remind myself of all the good ways these health conditions have improved not only me as person, but my life and impact on the world too.

Have you found that your thyroid condition has changed your personality in any way?

You can click on the hyperlinks in the above post to learn more and see references to information given.Be Your Own Thyroid Advocate Book Cover

See also:

The book Be Your Own Thyroid Advocate: When You’re Sick and Tired of Being Sick and Tiredwhich builds on this article. Reclaim your thyroid healthy life.

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".


  • Eri
    November 25, 2019 at 9:18 am

    Great article Rachel. I have been thinking of this just the other day. I was diagnosed recently and fortunately it did not take as long as in some cases. 2 years ago the antibodies did not exist now they do, however I have been having symptoms already 2 years ago. My life changed completely. I used to be super active as well, I used to ‘drive’ and motivate my peers and my colleagues at work, organizing social events, I did a lot of sports, a lot of house works. Seemed I did not have to rest. Was considered brilliant at work dealing with stressful situations. Now I am happy that in this moment I don’t have to work as I would struggle. I am not able to handle stress in any form, whatever seems just overwhelming. Even a family dinner, or having friends at home for dinner brings me to a flare-up and I need to recover for days and on the day the dinner takes place I am irritated and people don’t enjoy myself. This ends up that I hate myself for my behavior and I am simply not able to manage it in that moment. I often seem to be to aggressive and rude to people (this was definitely not myself before). Also the way I am doing sports and recovering changed a lot. I am still able to do CrossFit classes, but it requires so much more energy,will power and time to recover. My body does not react to stimulation as it used to, I don’t put on muscles as easy, sometimes I get just bloated after heavy workout and this means I need to slow down the next time as I feel it was too stressy for my body.
    Today, I feel lucky I got the diagnosis quite quickly and I have a plan of treatment with a functional medicine specialist. This makes all the things so much brighter in my mind.

  • John Tremelling
    October 24, 2019 at 8:22 am

    As a man suffering from Hypothyroidism I also had my life completely changed in my mid-thirties, I am now seventy three.
    I was a martial arts instructor, worked out regularly in the gym and regularly did high impact high intensity aerobics. Before my diagnosis I found I was getting weaker and became depressed. My marriage broke down and I was so broken I could not run my business or undertake daily tasks.
    It was some time before I had a diagnoses and treatment but even then I never fully recovered. My sex drive had gone and truly never ever returned. Each single day of my life has been a nightmare and my body frequently lets me down in one way or another.
    I understand that this condition is often seen as a ‘woman’s illness’ but I can assure everyone that for men it also is devastating.

  • Lulu
    October 22, 2019 at 9:50 am

    A great post,Rachel. Thank you. It seems as though I have experienced the same difficulties as you in terms of brain fog, poor concentration. I was a teen when I developed the symptoms but they went diagnosed for 10 years,so my education was definitely affected. As the symptoms developed, my fatigue affected my relationships. Called lazy…… I definitely look after myself now and listen to my body. If people have a problem with, that is exactly how I see it; their problem. I shouldn’t need to justify myself or feel guilty. Luckily, I can work from home, which is a benefit due to meds and supplements I need throughout the day.

    • Rachel Hill
      October 22, 2019 at 9:53 am

      Hi Lulu, sorry to hear your went undiagnosed for so long and with such debilitating symptoms too. It’s such as shame as you can’t go back and redo a lot of your education. We have to look after ourselves, you’re right. I feel lucky that I work from home too as it makes working with a thyroid condition much more manageable.

  • Caz / InvisiblyMe
    October 22, 2019 at 8:42 am

    This is such a poignant topic to cover, and I agree that chronic illness has changed my life, turned it upside down really, including my personality. When considering the mental aspects, ‘brain fog’ is a big one that frustrates me. It’s affected my personality in ways I don’t like and need to work on (negativity, far too stressy). But, like you’ve said, I’ve also found I’m a heck of a lot more assertive than I ever used to be, and I’m far more appreciative of the small, simple things in life. xx


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