It's estimated that up to 10% of people in the US have subclinical hypothyroidism.
Statistically speaking that means you have a pretty high chance of having this issue even if you have tested "normal" for thyroid lab tests.
Because subclinical hypothyroidism represents a treatable condition on the hypothyroid spectrum it's critical to accurately diagnose and treat this condition early.
Failure to treat can lead to overt hypothyroidism and worsening symptoms down the line.
In this guide I will walk you through everything you need to know about subclinical hypothyroidism including 5 reasons you should treat the condition ASAP:
What is Subclinical Hypothyroidism?
So what is subclinical hypothyroidism?
By definition, it's supposed to indicate a state of thyroid function in the body that manifests as a change in thyroid stimulating hormone (TSH) without manifesting with the symptoms of hypothyroidism.
You can think of it as a reduction in efficiency in the entire thyroid system, but still that the thyroid is producing enough thyroid hormone for the body.
Or is it?
While that's what the exact definition is supposed to mean, most patients who actually have subclinical hypothyroidism manifest in a completely different way.
Most patients with abnormal thyroid hormone levels, including abnormal TSH levels, do indeed have some degree of hypothyroidism.
But, unfortunately, due to a variety of reasons, including the current treatment paradigm for hypothyroid patients, these patients are usually ignored or given the "wait and see" approach.
But let's evaluate that to see if it actually stands on its own.
When you go to the Doctors office it's usually because you aren't feeling well.
Most people who think they have thyroid issues (you guys are right by the way) come in because they've done their research and they are tired of feeling poorly.
They often present with weight gain, fatigue, low energy, changes to their mood, hair loss, etc. (we will discuss more symptoms below).
These symptoms are not just the "normal" signs of getting older.
They are, in fact, symptoms that coincide with hypothyroidism directly and they should be treated as such.
But let's go back to the standard of care, the "wait and see" approach to managing subclinical hypothyroidism for a second.
What is it?
In the most basic sense it is your Doctor saying to you, let's just monitor your thyroid level, even though you feel terrible, for another 6-12 months.
Once your thyroid lab tests finally go into the "abnormal" range, then we will treat you with thyroid hormone.
This approach usually leads to poor quality of life on behalf of the patients, and frustration on behalf of the physician.
We are going to talk today about a better approach to managing subclinical hypothyroidism and what it actually means.
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TSH Levels and Subclinical Hypothyroidism
In most cases, Doctors rely heavily on the serum test known as thyroid stimulating hormone.
They suppose that this test, in isolation, offers a perfect view of thyroid function in the entire body and that all treatment should be based on this one test.
This is in spite of studies like this (1), which show that TSH levels do not mean you have adequate T3 and T4 circulating levels of thyroid hormone in the serum.
And studies like this (2), which show that not all patients equally convert T4 to T3 in peripheral tissues.
Or facts like this (3), which point out that pituitary tissues have different deiodinases than peripheral tissues and so each reacts differently to thyroid hormone.
So what's the bottom line?
It's not hard to see that evaluating for subclinical hypothyroidism or hypothyroidism is probably best done with more testing than just the TSH.
I discuss a complete set of thyroid lab tests that you should be ordering in this post here for those that are interested.
Even though we've established why the TSH is not the best marker, it's still a decent marker for establishing if you have subclinical hypothyroidism so let's talk about the ranges for just a moment.
From a conventional standpoint, here are the reference ranges that your Doctor will likely be using when diagnosing subclinical hypothyroidism and hypothyroidism:
- TSH range from 5-10uU/ml is usually considered subclinical hypothyroidism
- If TSH is between 5-10 recheck labs in 6 months
- TSH greater than 10 uU/ml is considered hypothyroidism and is usually treated with Levothyroxine monotherapy
I don't recommend following these lab ranges, for various reasons which we will discuss above, but I am telling you what you can expect if you walk into the Doctors office.
Now compare those standard ranges to the more optimal ranges:
- TSH range greater than 2.0 uU/ml is consistent with hypothyroidism and therefore should be treated with thyroid replacement therapy, preferably a combination of T4 and T3 based on conversion status
- Free T3, free T4 and reverse T3 levels should be evaluated to determine peripheral conversion status
- Thyroid antibodies should be evaluated to determine if autoimmune thyroiditis is impairing thyroid function
- Inflammatory markers should be evaluated to determine if they are contributing to peripheral thyroid conversion
Which of these sounds better to you as a patient?
The more comprehensive approach should sound better and simply seem more logical than the initial and more standard approach.
But let's take a minute to talk about the symptoms of hypothyroidism so we can build our case for why you should treat subclinical hypothyroidism.
Symptoms of Subclinical Hypothyroidism
Symptoms are very important for the diagnosis of subclinical hypothyroidism.
Because in the absence of abnormal symptoms all you have is an abnormal lab value.
You (and your Doctor) ALWAYS should be evaluating lab values with the patient in mind!
That means evaluating lab values in the context of symptoms, hormone imbalances, nutrient deficiencies and so on.
Never treat based on lab values alone.
Which brings us to the next point:
What are the symptoms of subclinical hypothyroidism?
It's important to consider that hypothyroidism, like other disease states, exists on a spectrum.
That means that each person can present differently and it means that the degree of your symptoms may change based on how bad your hypothyroidism is.
Subclinical hypothyroidism is ON this spectrum, meaning it is a form of hypothyroidism.
Usually, subclinical hypothyroidism presents with the EXACT same symptoms as hypothyroidism but just to a lesser extent.
For instance, most patients with hypothyroidism usually have 30-50 pounds of weight gain, but most people with subclinical hypothyroidism only have 5-15 pounds of weight gain.
Both conditions present with similar symptoms, but not to the same degree.
Below is a graph which shows the symptoms of subclinical hypothyroid patients compared to normal euthyroid patients.
It's easy to see that patients with subclinical hypothyroidism present with almost ALL of the symptoms of hypothyroidism when compared to "healthy" adults.
I've included a list of the symptoms of subclinical hypothyroidism below:
- Weight gain (usually only 5-15 pounds)
- Fatigue (not crushing fatigue, but low energy throughout the day or reliance upon caffeine for energy)
- Cold hands and cold feet
- Inability to lose weight or difficulty losing weight (especially if you were able to lose weight in the past)
- Dry hair or a history of alopecia (usually not overt hair loss)
- Decreased memory
- Dry skin or other skin changes
- Swelling in the neck, hoarseness or presence of a goiter
- Constipation or other GI related issues (usually mild constipation)
You can compare the symptoms of subclinical hypothyroidism to the overt symptoms of hypothyroidism here.
Reasons to Treat Subclinical Hypothyroidism
Now that you understand what subclinical hypothyroidism is and how to properly diagnose it, let's talk about why you should be treating it.
I understand that many of you probably want to treat your condition but receive push back from your doctor.
If you fall into that category then you may want to seek out an alternative physician who is more willing to work with you.
Let's jump in:
#1. Subclinical Hypothyroidism is still on the Hypothyroidism Spectrum
The first and probably most important reason to treat subclinical hypothyroidism is that it is on the hypothyroidism spectrum.
You can really consider subclinical hypothyroidism as just a mild form of hypothyroidism and therefore it should be treated in a similar way.
What's important here is that patients who have subclinical hypothyroidism suffer from the symptoms of hypothyroidism and, as a result, suffer with a low quality of life.
This means that if you've been told you have subclinical hypothyroidism you stand to benefit tremendously from thyroid hormone replacement.
At the very least, you should do some digging to see WHY you developed the condition in the first place.
Because abnormalities in thyroid function stem from some root cause, and if you can identify and treat that cause you can reverse the condition before it progresses to overt hypothyroidism.
#2. You may have Autoimmune Thyroiditis and not know it
I mentioned previously that it's important to find the CAUSE of your subclinical hypothyroidism.
Well, one of the most common causes of decreased thyroid function in the US is autoimmune thyroiditis.
In fact, up to 70-90% (depending on which studies you look at) implicate autoimmune thyroiditis like Hashimoto's as the primary cause of hypothyroidism in developed countries.
Why is this important?
Well, for several reasons:
It turns out that mild inflammation and autoimmunity in your thyroid gland may eventually lead to irreversible damage and complete reliance upon thyroid medication.
Beyond that, and more importantly, is that you may be able to stop the inflammation (or at least slow it down) and prevent further damage.
Most physicians don't even check thyroid antibodies, even in the presence of hypothyroid symptoms, which means it's up to you to ask for these tests.
They are very standard tests, and you shouldn't get push back for asking for them.
#3. Impaired thyroid function causes dyslipidemia
Another very important reason to treat subclinical hypothyroidism is because of its effects on lipid regulation in the body.
Even slightly low amounts of thyroid hormone can contribute to changes in cholesterol levels leading to dyslipidemia and hyperlipidemia.
Those names are just fancy ways to describe high cholesterol that leads to an increased risk of heart attack and stroke.
Most physicians forget the important connection between thyroid hormone and cholesterol regulation in the liver.
Studies have shown that subclinical hypothyroidism (4) leads to higher levels of LDL-C and triglyceride levels in the serum.
This same study showed that TSH levels between 2-4 uU/ml in patients with elevated antibody levels (showing signs of autoimmune thyroiditis) also have abnormal cholesterol levels.
Your thyroid influences so much more than just your energy levels, it's also very important in regulating other factors in your body such as metabolism and cholesterol levels.
Which brings us to point #4...
#4. Low thyroid makes weight loss very difficult
It's rare nowadays for me to find someone who is NOT interested in weight loss.
You probably know that low thyroid contributes to weight gain, but what you may not have realized is that low thyroid also contributes to weight loss resistance.
What does this mean for you?
It means that patients with subclinical hypothyroidism are not only at a higher risk for weight gain, but it will also be more difficult to lose that weight if they try.
Most patients who have subclinical hypothyroidism relate to the fact that they USED to be able to lose weight but haven't been able to lose weight recently - even by using old strategies.
This should tip you off that something is off in your body.
Remember that weight gain is the product of hormone imbalances in your body and thyroid hormone is heavily involved in regulating your metabolism and thus your weight.
You can read more about how low thyroid contributes to weight gain here.
#5. You can feel like your old self again
One thing I've noticed from patients is that they know when they are "off" or when they just don't feel like their "old self".
This phenomenon is especially true of patients with hypothyroidism (either diagnosed or suspected).
Your thyroid is involved in multiple biochemical functions in your body and helps regulate your mood, metabolism, GI function, energy levels and so much more.
Even small changes to thyroid function may result in the symptoms we discussed above.
Many patients take their complaints to their Doctors only to be dismissed or given an anti-depressant.
If the cause of your symptoms is related to thyroid status then no amount of anti-depressant will be able to help.
So, lastly, this is probably the most important reason to consider getting treatment for subclinical hypothyroidism.
Is Subclinical Hypothyroidism Reversible?
While subclinical hypothyroidism represents a problem in your body and in your hormones, it also represents the opportunity to catch a problem before it snowballs out of control.
For this reason, it's very important to get the diagnosis early so that you can seek out and find the problem.
One question you might be asking yourself is this:
Can I improve my thyroid function?
And the answer is almost always yes, to some degree.
Because most physicians aren't really willing to prescribe thyroid hormone for this condition (some will) that leaves you with the ability to take matters into your own hands and take some steps to improve your thyroid function.
Treating Subclinical Hypothyroidism Naturally
If you've recently been diagnosed with subclinical hypothyroidism and want to be active and aggressive about your condition I recommend starting with these tips:
*Note you may ultimately need physician help to get proper treatment, but you can start here.
#1. Address basic nutrient deficiencies in your body.
You can easily evaluate for basic vitamin deficiencies like B12, Vitamin D3, Folic acid, and omega 3 fatty acids.
In addition, many patients have existing deficiencies of nutrients like zinc and selenium.
Simply checking for and replacing (if you are deficient) can often time dramatically reduce symptoms.
#2. Check to see if your impaired thyroid status is due to Hashimoto's or autoimmune thyroiditis.
Finding out your subclinical hypothyroidism is caused by an autoimmune disease can be stressful but it also represents another treatment option for you.
If you know you fall into this category make sure you make changes to your diet, you can read more outlined in this post.
And take further steps to help reduce your antibody level which will, in turn, increase your thyroid function.
#3. Check for and reduce systemic inflammation in your body.
Inflammation causes reduced thyroid function and can lead to other hormone imbalances that lead to weight gain.
You can check for inflammation by assessing your serum ESR, CRP and ferritin levels (all easy tests to ask your Doctor for).
#4. Consider iodine replacement therapy.
Iodine is required for proper thyroid hormone production and if your diet isn't high in iodinated salt or seafood then chances are you may have suboptimal levels.
In some patients, taking iodine is enough to completely reverse and normalize thyroid status.
Supplementing with iodine doesn't have to be tricky, in this post I explain exactly what to consider and how to do it.
#5. Take steps to boost T4 to T3 conversion to maximize existing thyroid hormone function.
Even if your Doctor isn't willing to work with you or give you thyroid hormone there are special steps that you can take to naturally improve your existing thyroid function.
You can do this by increasing T4 to T3 conversion which creates more of the active and free thyroid hormone in your body.
Back to you
Remember that subclinical hypothyroidism is and should be considered a treatable condition on the hypothyroid spectrum.
Failure to treat this condition, or failure to dig deeper as to the root cause, may result in overt hypothyroidism later in your life.
For this reason, I recommend that you treat this condition aggressively and that you get further and more advanced testing to figure out what is happening in your body.
If you've been diagnosed (or if you suspect you have) subclinical hypothyroidism I want to hear from you.
What steps have you taken to treat your condition?
Is your physician willing to work with you and put you on thyroid hormone?
Leave your comments or questions below!
References (Click to Expand)
This post was most recently updated on February 19th, 2019