Thyroid Hormone Status Explained In Plain English
Is it possible to be both hyperthyroid and hypothyroid at the same time?
I'm going to give you the answer now and then explain why that is the case in more detail.
The short answer is no.
It is not possible for the same cell or the same tissue in your body to be both hyperthyroid and hypothyroid at the same time.
Does that mean that you cannot have both hyperthyroid and hypothyroidism symptoms simultaneously?
No, that is very possible and I will explain why later in this article.
But for now, we need to have a discussion on thyroid hormone status.
The reason that a single cell or tissue cannot be both hyperthyroid and hypothyroid at the same time has to do with how thyroid hormone impacts your cells.
Each cell has a receptor for thyroid hormone, usually located in the nucleus of the cell (1), which must be turned on.
This nuclear receptor, when activated, turns on genetic transcriptions and results in changes to the enzymes that are being produced by your cells.
What you need to understand is that this system can either be turned on or not.
It can either be stimulated or not.
It cannot be both stimulated and not stimulated at the same time which means that you can't be both hyperthyroid and hypothyroid in the SAME tissue at the SAME time.
Having said that, how is it possible for some people to experience SOME symptoms of hyperthyroidism and SOME symptoms of hypothyroidism at the same time?
The answer is quite simple and it has to do with the thyroid hormone status of individual cells and tissues.
Another common reason for changes in your symptoms has to do with alternating thyroid function and confusion regarding your symptoms.
If you are experiencing both hyper and hypo symptoms then these next two sections are REALLY important to understand.
As we talk about them you should be able to figure out which group you fall into which should then help explain how you are feeling.
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Conditions which Cause Alternating Thyroid Function
The first group of people who experience both hyper and hypo symptoms are those who have conditions that result in variable thyroid function.
What I mean by that is this:
Some conditions which impact your thyroid can cause you to experience hypothyroid symptoms for a period of time but then switch to hyperthyroid symptoms.
As you might imagine, this can be incredibly confusing for thyroid patients.
Thyroid function exists on a scale between hyperthyroid, normal thyroid, and hypothyroid.
Consider this scenario...
On day 4 you have normal thyroid function and your previous symptoms are subsiding.
On day 8 you have hyperthyroid symptoms and now you are experiencing heart palpitations, diarrhea, and heat intolerance.
On day 14 you have normal thyroid function and now you notice that your previous symptoms are improving again.
And then on day 20, you go back to hypothyroid symptoms and now you are starting to experience the SAME symptoms you did 20 days ago including fatigue, weight gain, and constipation.
Over a 20 day period your thyroid has swung back and forth between hypo, hyper, and normal thyroid function.
Can you see how confusing this can be if you aren't actually keeping track of your symptoms exactly?
It would be really easy to just assume that you are experiencing both hyper and hypo symptoms at the same time even though that isn't actually the case.
Instead, what is happening is that your body is alternating between hypo and hyper states so quickly that it's hard to keep track.
While it may feel that you are both hyper and hypo at the same time, I can assure you that you are not.
Instead, you are alternating quickly (or not) between these two states.
And only a handful of thyroid conditions cause this issue.
- Thyroiditis of any type - Thyroiditis simply refers to inflammation of the thyroid gland and this can be caused by a number of conditions. Trauma, bacterial infection, viral infection, pregnancy, and so on, can all lead to inflammation in the thyroid gland itself. Most cases of thyroiditis cause fluctuating thyroid hormone but do resolve over time. Official names include subacute thyroiditis, postpartum thyroiditis, silent thyroiditis, and medication induced thyroiditis.
- Hashimoto's thyroiditis - Hashimoto's is the most common cause of hypothyroidism and it is also the most common cause of thyroiditis. Unfortunately, Hashimoto's typically does NOT go away like the other types of thyroiditis. Alternating thyroid function in Hashimoto's only occurs in about 10-15% of patients (2) so it's not super common but it does happen.
- Thyroid Medication - Thyroid medication can cause you to shift between being hypo and hyper and is actually more common than you think! In fact, most of the symptoms that people experience while taking thyroid medication are caused by changes in their dose. Taking too much thyroid medication may lead to hyper symptoms and taking too little may lead to hypo symptoms. Because there is a lag time between taking thyroid medication and feeling better (about 6 weeks on average), it's not uncommon for impatient people to prematurely adjust their dose and experience either hypo or hyper symptoms.
- Antithyroid medication - Just like thyroid medication, antithyroid medication can also impact your thyroid status. Antithyroid medication is primarily used to treat hyperthyroid conditions but you can imagine that it's fairly easy to cause confusion for patients. Taking a high dose of antithyroid medication can cause hypothyroidism (even though you are technically 'hyperthyroid') and not taking enough may leave you feeling hyperthyroid.
Before moving on to the next section, check to see if your symptoms can be explained by your thyroid condition or the thyroid medication you are taking.
If this doesn't explain your symptoms then the next section will.
Tissue Sensitivity to Thyroid Hormone
This section is all about tissue sensitivity to thyroid hormone and this problem explains why many people feel they are experiencing both hyper and hypo symptoms at the same time.
What you need to understand here is that not every tissue in your body is equally sensitive to thyroid hormone.
Put another way, some tissues and organs in your body are MORE sensitive to thyroid hormone compared to others.
From the perspective of thyroid hormone, your body is a big place.
The hormone that is secreted by your thyroid gland must make it to pretty much every single cell in your body.
Skin cells, heart cells, liver cells, brain cells, and so on all have a need for thyroid hormone.
But, as you can imagine, thyroid hormone will make it to some tissues faster than others (just based on proximity from where it is released) and some tissues are more resistant to thyroid hormone compared to others.
This may lead to some tissues getting OVER stimulated and other tissues getting UNDER stimulated even though they are both exposed to the SAME dose of thyroid hormone.
Let me give you a practical example to help this sink in:
As it turns out, your heart is quite sensitive to thyroid hormone (3), especially compared to other tissues.
Thyroid hormone that is taken by mouth is absorbed in the GI tract, taken through the liver, and straight to the heart to be pumped throughout the body.
Heart cells have different thyroid receptors compared to other cells in the body, though.
And these cells are on the outside of the cell (4).
When these receptors are triggered they cause your heart to beat stronger and faster (with more force).
This is often felt as either a rapid heart rate or as a heart palpitation.
Knowing this, imagine taking a dose of thyroid medication by mouth which goes straight to your heart and causes heart palpitations and a rapid heart rate for a short period of time.
For this short moment, your heart is experiencing overstimulation of thyroid hormone but it will take WEEKS for that same dose of thyroid hormone to impact your other cells to help your hair grow back and to help provide you with energy.
It's not necessarily that your dose of thyroid medication was too high but instead that one of your tissues is more sensitive to thyroid hormone compared to the rest.
This phenomenon allows you to experience hyperthyroid symptoms in one specific tissue even though you are more hypothyroid overall in the rest of your body than hyperthyroid.
As you might suspect, this is the source of MUCH confusion for thyroid patients!
And the heart isn't the only tissue that this occurs in.
Below you will find a list of tissues or organs in your body which tend to be either resistant or sensitive to thyroid hormone:
- Heart Tissue - We already discussed why your heart cells tend to be more sensitive to thyroid hormone compared to other areas of the body.
- Brain Tissue - With the exception of the pituitary gland (5) (which is very sensitive to thyroid hormone) the brain tends to be a little bit resistant to thyroid hormone. This typically manifests as symptoms such as depression, anxiety, and even bipolar disorder. When taking thyroid medication by mouth, you may notice that these mood related issues take a lot longer to resolve compared to other hypothyroid symptoms in your body. When it comes to managing these symptoms, thyroid medications that contain T3 tend to work best.
- Skin Tissue - The skin is another tissue that tends to be resistant to thyroid medication. This usually manifests as cystic acne in people who experience this problem. This type of acne is often related to the thyroid and can be very hard to treat unless the right dose of thyroid medication is used.
- Hair Follicles - Attached to the skin are hair follicles that are also sensitive to thyroid hormone. Too little thyroid hormone and too much thyroid hormone can both cause issues with hair loss, hair growth, and the quality of the hair. Many women with thyroid problems continue to have issues with their hair even when other thyroid symptoms have resolved.
- Metabolism - Another big area is your metabolism. Your thyroid regulates a huge percentage of your overall metabolism which means that low thyroid leads to weight gain. But let me ask you this: you probably gained weight before you were diagnosed with hypothyroidism but did you lose that weight when you started taking your thyroid medication? Probably not, as persistent weight gain is a huge problem for many thyroid patients. This is because the metabolism lags behind other tissues and indicators of thyroid function in the body. I've seen numerous women who have near complete control of their thyroid symptoms but still struggle to lose weight.
Wrapping It Up
Figuring out what is happening in your body with your thyroid may require some investigative work but it will be well worth the effort.
If you are experiencing symptoms that coincide with both hyperthyroidism and hypothyroidism then a deeper look is warranted.
As you do this, ask yourself these questions:
Is it possible that your thyroid CONDITION is causing the swings in your thyroid status from hypothyroid to hyperthyroid?
Or do you think that it is more likely that some of your tissues are being overstimulated by thyroid hormone (or thyroid medication) and other tissues are being understimulated?
In my experience, the second situation tends to be more likely than the first but they both can and do occur!
Now I want to hear from you:
Are you experiencing BOTH hyper and hypothyroid symptoms?
If so, what type of symptoms are you experiencing?
Do you feel it's related to your thyroid function or to your thyroid medication?
Or do you think it's related to the different sensitivities of thyroid hormone in your tissues?
Leave your questions or comments below!
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