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Originally published on 12th May 2016 Last updated on 25th July 2021
I refer to days when my hypothyroid or Hashimoto’s symptoms are particularly bad as a ‘bad thyroid day’. Also called ‘flare ups’, I’ve had these days when my thyroid condition hasn’t been under control and when it has.
My Hashimoto’s is currently in remission, yet I can still experience them from time to time.
Even now, with optimal TSH, Free T3 and Free T4 levels, as well as low thyroid antibody levels, I can still have flare ups.
What Is a ‘Flare Up’?
A Hashimoto’s or thyroid flare up is defined by an increase in symptoms of these conditions. A flare usually occurs for a few days but up to a few weeks.
However, if you’re feeling that they’re going on much longer than this, it could actually not be a flare up, but a permanent dropping of your thyroid hormone levels. After all, flare ups are not associated with a drop in thyroid hormone levels, but are more a reaction to overexertion which takes your body a day or two to recover from. Read more here.
Symptoms can differ from person to person, though the most commonly reported in a flare up are:
- Increased fatigue
- Heaviness (as if your body is being weighed down)
- Worsened mental health
- Brain fog
- Flu-like symptoms (aches and pains)
- Switching between feeling really cold and really hot
Related post: Thyroid Patients Explain How Their Flare Ups Feel
What Causes a Flare Up?
These are the most common triggers according to thyroid patients:
- Drinking alcohol
- Eating poorly (such as a lot of sugary or processed food, not giving your body good nutrition)
- Consuming a known food allergen or sensitivity (such as gluten, dairy, soy etc.)
- Overexertion (mentally and/or physically) – See the spoons post
- Not sticking to a good sleep routine
- Viral, bacterial, fungal etc. infections
- Being on your period or due to start on your period (hormone fluctuations)
If you’re stuck in flare up cycles, it may be because you’re doing something like this:
- Over exercising
- Doing all the things
- Running yourself in to the ground tired
- Forced to stop exercising and running around because your body collapses
- Forced to rest and recuperate
- Repeat over and over again
So in order to prevent more flares, we need to break this cycle!
How Can I Avoid Flare Ups in Future?
Each time you experience one, try to pinpoint what things (such as those listed above) have contributed to it. Obviously the main thing to do here is then avoid them in future if possible, so as to reduce the chances of another flare.
Some people find relief from flare-ups when they eliminate a food allergy or sensitivity, such as gluten. Around 90% of people with hypothyroidism have the autoimmune disease Hashimoto’s, which is the cause for their hypothyroidism. 
Many don’t even know it, though, and for these people, cutting out gluten from their diet is often cited to help control thyroid antibodies and ease symptoms, helping them reduce the amount of future flare ups.
You can also look at quieting the immune response by lowing your thyroid antibodies if you have Hashimoto’s, which can even lead to the condition being in remission. By lowering thyroid antibodies, we’re told that this puts the condition under control and means it is better managed, reducing symptoms and flare ups. See this article for ways to do this.
Supporting your immune system and body as a whole with good nutrition, supplements such as Vitamin C, D and Selenium, adequate sleep and keeping stress levels low can also help.
Ensuring you are also addressing any adrenal dysfunction is also very key, as adrenal fatigue (though it is more accurately referred to as hypothalamic-pituitary axis dysfunction) often goes hand in hand with hypothyroidism and can cause many of the same symptoms.
Having your thyroid levels tested regularly and ensuring they are all optimised is also key to feeling well with thyroid disease.
What Should I Do in a Flare Up?
First and foremost, it is important to say that if you’re feeling incredibly unwell, then you should always see your doctor in case something more serious is going on. If what you initially think is a flare up actually carries on for weeks or months, it is probably more likely a sign of a thyroid medication dosage adjustment or need for other investigations.
How To Manage Flare Ups When They Happen
The bad thyroid days are a part of having hypothyroidism that I have learnt to accept with time, but I did, at one point, think I would be able to make a 100% recovery back to full health, without any flare ups ever again. But you know what? No one person is in perfect health every single day of their lives. And so it’s perfectly normal to expect flare ups in symptoms from time to time.
Now I realise it’s OK and normal to have bad health days. My health is always going to require close monitoring to try and keep it on track as much as possible.
As thyroid patients, we do often expect a bit too much from ourselves, too. And I’m very guilty of this!
On a bad thyroid day or flare up day, I like to rest, keep warm, put on some films or a TV boxset, and drink lots of warm drinks such as hot water and lemon, or herbal tea, keeping myself well hydrated. I eat nourishing food, enjoy bone broths and might even call a friend or two for some company. But if I don’t feel sociable, then that’s OK too.
I listen to my body and let it have whatever it needs to get over this flare. I often like to try and get in the bath (if I have the time) as this helps my body loosen up, but hot water bottles can also really help with this too.
On days where I have had to work or otherwise didn’t have the luxury of just resting in front of the TV or in bed, I have compromised. I can try to limit how much work or other commitments impede my recovery from a flare up. For example, seeking permission to work from home, working altered hours until the flare has passed, replacing walking to and from work with transport to save energy, or otherwise speaking to my line manager about suitable adjustments.
If making changes surrounding my work isn’t an option, at the very least I can support recuperating outside of work as much as possible. I limit how much unnecessary activity I do and maximise resting and recuperation time instead. Learn to say “no”. I avoid sugar and caffeine and other stimulants that place additional stress on the endocrine system, and eat nutrient dense food to nourish me and aid my recovery.
It’s OK to not be 100% well everyday. It’s OK to look after yourself.
If I can, I’ll take a bath and relax, listen to music… anything that helps me feel well cared for.
But most importantly: take it easy.
Don’t over-do anything, as you’ll just make it worse, so instead listen to your body and do not in anyway overexert it during a flare up. Don’t do anything requiring too much from you mentally, physically or emotionally. Just rest and look after your body. After all, you only get one.
What are thyroid flare ups like for you?
You can click on the hyperlinks in the above post to learn more and see references to information given.
Please remember that if you’re a thyroid patient living with poor mental health or lingering physical symptoms, that you don’t have to live this way. To address why you may still be feeling unwell (often despite being on thyroid medication too), please see this article and go through each suggestion, putting your thyroid jigsaw back together.
The book Be Your Own Thyroid Advocate: When You’re Sick and Tired of Being Sick and Tired, which builds on this article in detail.
The online thyroid course ‘Freedom From Thyroid Fatigue’, also walks you through how to overcome thyroid fatigue and flare up days with a personalised approach.
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, as well as being a founding board member for the American College of Thyroidology. She is well-recognised as a crucial contributor to the thyroid community and has a large social media presence. Her books include “Be Your Own Thyroid Advocate” and “You, Me and Hypothyroidism”.