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Are you wondering what are the common Hashimoto's flare up symptoms? In this post I share the common symptoms that many suffer from and how to know if you're having a flare. Hashimoto's flares can be scary – and so random, so don't suffer without having the peace of mind that you aren't alone in your symptoms. Plus – why medications don't necessarily help with a flare.

Due to how much my post Dealing with A Hashimoto's Flare has struck a chord with so many people, I wanted to offer this post as well so you can see what the Hashimoto's flare up symptoms are.

Because it's such an ambiguous autoimmune disease without any particular defineable A, B, and C symptoms, it's often helpful to hear what others experience so that you can feel a bit better knowing you aren't alone.

What Makes Hashimoto's Symptoms Unique

Most people, at least in the US and other developed countries, do not get glandular hypothyroidism or hyperthyroidism (though it can happen, and there are some other forms too, like temporary postpartum hypothyroidism).

Instead, most people with hypothyroidism actually have an autoimmune form of thyroid disease called Hashimoto's thyroiditis, or at least their hypothyroid/hyperthyroid is rooted in autoimmune disease. Many cases of hyperthyroidism are rooted in Grave's Disease. (In third world countries it's more common to suffer from a lack of iodine and the root cause is truly glandular)

a line drawing of a thyroid gland

Why Is It Important That It's Autoimmune?

This is important because people tend to start feeling symptoms of either hypothyroidism or hyperthyroidism when they first see a doctor, and the doctor will diagnose them with one of these – but it doesn't tell the whole story.

When you first go to see a doctor with symptoms, they typically run a TSH (Thyroid Stimulating Hormone) test.

If you have abnormally low TSH, the doctor will diagnose you as “Hyperthyroid”.

If your TSH is high, then you're “Hypothyroid”.

Usually at that time your symptoms even line up with these lab results and diagnoses. For instance, if you were to go read an article about “Hypothyroid symptoms”, you'd agree with many, if not all.

However, as time goes on, people usually start to feel symptoms of BOTH hypothyroidism AND hyperthyroidism.

This gets confusing because your test results say one thing and you're typically on medication to help with the condition, but you're experiencing something totally different than what you'd expect.

Why Do You Feel Both Types of Symptoms?

This happens because your disease is autoimmune in nature, which means you have a progressive disease raging on in your body that is not being healed, no matter what dosage of medication you're on.

Just looking at TSH and diagnosing as hypothyroid or hyperthyroid looks at one small piece of the whole puzzle.

People with Hashimoto's often experience symptoms of both Hypo- and Hyperthyroidism, as well as many other symptoms that are common to autoimmune disorders in general.

List of Hashimoto's Flare Up Symptoms

This list below are the common symptoms that someone suffering from Hashimoto's thyroiditis may experience. There are others that aren't on this list, but these are the ones I've found to be most common amongst the clients I've worked with and those in my community.

If you prefer to watch rather than read, this full-length YouTube video details all of the Hashimoto's flare up symptoms as well:

These symptoms are common if you've not done anything at all or if you've treated your disease with medication, and are also common flare up symptoms even if you've put your disease into remission (typically through diet and lifestyle changes).

Physical Hashimoto's Symptoms

Cold hands and feet – this one's pretty self explanatory, but you may notice your hands and feel getting cold all the time, or you always need socks and/or gloves

Intolerance to cold or heat – many with Hashi's just generally are colder than other people and may need to pile on sweaters, coats, and blankets even if it's 90 F out. Or the opposite may occur, where heat just wipes them out faster than anyone around them

Excessive hair loss – this can be from your head or body but most likely involves a lot more hair than usual. This also includes thinning eyebrows and eyebrows that won't grow back.

Dry hands and feet or dry skin in general – a higher fat diet can help with this, but this is a common symptom

Extreme fatigue – This is one of the most common yet worst symptoms of Hashi's – this exhaustion doesn't get better with sleep, no matter how much sleep you get. Often people with Hashimoto's can sleep 12-15 hours a night plus naps and still feel tired – and it's a bone deep tiredness.

Heavy or nonexistent and/or Irregular Periods and Menstrual Cycles – Heavy periods are not fun (I know from experience) and women with “normal” periods gasp at the amount of blood loss you might suffer from (it's so heavy it can be measured in cups, not ounces). In addition, the number of days in your cycle can vary greatly from month to month, and spotting in between periods can be quite common as well. Sometimes women experience nonexistent periods, but it is more common for them to lean towards the excessive side.

Body aches and joint pain – These can range from vague aches to acute painful aches, and the joint pain can be similar to arthritic pain. It seems to migrate sometimes – one day in your hands, the next in your knees, the next in your teeth, and so on…

Heart Palpitations – These can include skipped or racing heart beats, and they sometimes come in clusters. **It's very important to get checked out by a cardiologist though to make sure there is no underlying issue with your heart.

Weight gain or loss – This could go either way, and some people experience a greatly increased appetite.

Blood Sugar Crashes – When you feel shaky, irritable, “hangry” even with eating a low-sugar and otherwise healthy diet. (This is probably a normal occurrence if you eat a high-sugar diet, no matter if you have Hashimoto's or not)

Bulging Eyes – This is usually more of a hyperthyroid and Grave's Disease symptom but it can be found in those with Hashi's as well.

Brain fog, hard to think – if you're not familiar with this, it's similar to how you might feel if you have a head cold and have a hard time thinking and concentrating. It feels like you're trying to wade through a marshmallow in order to understand something or answer a question. It may take you several times reading something to comprehend it, and often it's hard to understand anything complicated, no matter how it's delivered (audio, video, written, etc)

Memory loss – this include both short and long term memory loss. If you often go into a room and think “wait, why was I here?”, this could be due to this. Also a hard time recalling names or things you may have just heard or learned.

Restless sleep & Insomnia – If you DO get sleep, it may be a restless sleep and involve a lot of insomnia, especially around 2-3 am and lasting for several hours after.

Anxiety and panic attacks – these days almost everyone seems to suffer from anxiety because that's what our society seems to promote, but this is almost uncontrollable anxiety, where there may not even be a logical explanation or stressor but you just have constant, sometimes debilitating, anxiety that can turn into panic attacks

Depression or apathy towards life and everything in it – Hashimoto's can be a cause of these feelings

Mood Swings – With these you might go from happy to sad or irritated, and without any sort of event triggering the change. They feel almost uncontrollable.

General Autoimmune Disease Symptoms

The following symptoms are ones that seem to be issues with anyone suffering from an active autoimmune disease, not just Hashimoto's.

Inability to fight off colds and viruses – and it seems you pick up every one you come near. Most likely due to the fact your immune system is already fighting so much and not regulated to fight the “real” fires

Seasonal Allergies – again, your immune system is ramped up and the response to allergens can be exaggerated

Digestive Issues – This includes gas, bloating, constipation, diarrhea – can be any or all and most likely due to either a gut infection, gut microbiota being imbalanced, or leaky gut leading to food intolerances.

Dizziness or vertigo – This one is another one that feels like you have a head cold, but you may not have the other symptoms of a cold. It can be really low-grade dizziness too, not always super noticeable, but annoying nonetheless.

Irritability – this goes along with the mood swings, but it's very common with autoimmune disease

Malaise, Generally not feeling well, low-grade fevers – You constantly feel like you're coming down with something like the flu, but it never turns into anything. It's just a period of time of feeling “ugh” and there's no real explanation for why it's happening.

Adrenal Fatigue Symptoms -these include being tired at 3 pm and sugar cravings

Adult acne and pimples – I don't know anyone who wants zits, no matter how old or young you are! But it feels just unfair to get them when you're an adult and past all that puberty stuff.

My Own Hashimoto's Flare Up Symptoms

Sometimes it helps to hear of a particular case, and in my own case, I get a TON of these when I have a Hashimoto's flare up.

My typical ones are:

  • heavy periods
  • irregular cycles
  • intolerance to cold
  • hair loss
  • adult acne
  • heart palpitations
  • brain fog
  • poor memory recall
  • ridiculous extreme fatigue
  • insomnia
  • joint pain that migrates throughout several parts of my body
  • anxiety (though it's never been as bad as it was before I did the AIP diet)
  • mood swings and irritability
  • inability to fight of colds and viruses
  • seasonal allergies
  • gas, bloating
  • dizziness
  • low-grade fevers and general not feeling well
  • adrenal fatigue symptoms
  • and I also get a low-grade sore throat that lasts for weeks – I haven't found this to be very common though, so I didn't mention it above

As you can see, it's not very fun to have a Hashimoto's flare! That's why I keep my Hashimoto's under control as much as I can using the Paleo diet.

How to Know If You're Having a Hashimoto's Flare and Not Just Sickness

It sometimes can be confusing to know whether your symptoms are Hashimoto's flare up symptoms or you're just coming down with a cold/flu/virus or something else.


The easiest way to determine this is to just give it time, as usually an acute illness like a virus will get worse quickly whereas Hashi's flares usually are a bit more slow moving.

It's important not to try not to freak out during this time and stress over whether you're having a flare or not – if you are, stress will only make it worse.

If you do think you're having one though, my post on dealing with a Hashimoto's flare might be helpful to read.

Thyroid Testing

Testing is the more accurate way of determining if you have autoimmune activity going on in your body.

a blood sample vial for testing for Hashimoto's flare up symptoms

The following are the tests that a doctor might run – be sure to ask for a “Full Thyroid Panel” if you want the antibody tests to be run as well:

TSH (Thyroid Stimulating Hormone) – this is the normal test that most doctors run that determines how much of the thyroid hormone T4 your thyroid is being asked to make. If your numbers are outside the lab normal ranges, then chances are you're having some sort of Hashimoto's activity in your body.

TPOAb (Thyroid Peroxidase Antibodies) – these will indicate if you have some sort of autoimmune activity against your thyroid

TGAb (Thyroglobulin Antibodies) – these will also indicate if you have some sort of autoimmune activity against your thyroid

Ultrasound – If the blood tests come back negative or if your doc wants to see more, they might do an ultrasound of your thyroid. There may be changes there that are consistent with Hashimoto's.

Needle biopsy – This is where cells are extracted from the thyroid via a needle and then studies under a microscope for signs of Hashimoto's. It's not a common way of determining Hashi's, but it can be something to use if no other test results show it.

To read more on thyroid testing, this article by Izabella Wentz is great.

Why Testing May Not Matter

Yes, it can be nice to have a piece of paper that says “You are in a Hashimoto's flare” and later see one that says you aren't.

However, if you're feeling these symptoms above and after a week or two have determined it's not from a cold or virus, and testing proves fruitless, I think it's more important to take measures to start reducing autoimmune activity in your body than to worry about a diagnosis.

Chances are, by reducing inflammation and immune activity, you'll start to feel better and the flare will calm down.

Note: If you're newly diagnosed or have never put your Hashi's into remission or felt better for a significant amount of time, check out my Start Here page as it will help guide you through what to do.

Why Medication Alone Won't Help Hashimoto's

Our bodies NEED thyroid hormones to work efficiently, and without sufficient quantities you'll never feel better.

thyroid pills in a woman's hand

Thyroid Medication Replaces Hormones

Therefore, it's very important to use replacement hormone medication (such as Synthroid, Levothyroxine, Armour, Cytomel, etc) if needed, as it will help replace the essential hormones your thyroid can no longer produce.

This will help you feel better and a lot of the symptoms above will go away as a result.

BUT – and this is a big but – the medications won't stop the progression of the disease in the background.

Wait What? The Disease Keeps Going?

You ever watch one of those movies where the thieves rig the security cameras to show a picture of the scene without anyone in it – so it looks like everything is ok?

Yet in the ACTUAL scene, they're wreaking havoc, stealing things, destroying things, etc?

That's how I see thyroid medications. They give you that false sense that everything is ok, but in reality, your immune system is having a destruction party.

The medications don't have the power to STOP the autoimmune disease, to stop your body from producing autoantibodies that attack and destroy your thyroid tissue.

That's why you may experience ups and downs all the time, good days and bad days, and fluctuations in your medication each month.

Eventually the medications don't even seem to help much at all, and you go to your doctor and they say there's not much they can do for you and/or it's “all in your head”.

What Works Then?

For many of us, changing our diets and lifestyle to a gluten-free, grain-free Paleo-style diet, with a LOT of stress reduction, emphasis on sleep and self-care, ideal amount of exercise, etc has done wonders, put our Hashimoto's into remission or at least made a significant improvement in symptoms, and reduced flare ups to very occasional situations.

The two best resources on my site to read are:

If you've already felt significantly better from your Hashi's and just experiencing a flare-up of symptoms, read Dealing with a Hashi's Flare

Also, if you're brand new to all of this, read the Start Here page, as it will guide you through all you need to know to help using diet and lifestyle changes to find relief.

Learn more about the Paleo & AIP Diets (my recommended diets for relieving Hashi's symptoms) via my Paleo & AIP Freebie Library.

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