Inside: Research-Backed reasons why people have a thyroid function test normal values but still have thyroid disease symptoms. What’s the underlying reason for thyroid symptoms. What can affect false thyroid test results?

Thyroid problems are very prevalent these days, especially in middle-aged women. Their prevalence is increasing day by day and many women suffer from terrible thyroid symptoms on a daily basis.

Hypothyroidism/Hashimoto’s disease come with a range of symptoms and oftentimes these symptoms can have multiple underlying reasons. 

There is a large number of women that we are seeing who have all thyroid disease symptoms with normal thyroid test results. 

So I get this question very commonly: “ Can my thyroid tests be false? “ or “Can my thyroid test results be normal and I can still have hypothyroidism”?

The Answer to these questions is not simple and a little complicated.

So to answer this question first we need to understand some basics about thyroid hormone production in our body. 

Thyroid Hormone Production

Thyroid hormone production is a fairly complex phenomenon. It starts all the way with the Hypothalamus area in your brain, this area of the brain produces a hormone called TRH ( Thyrotropin Releasing Hormone ). This hormone goes to the pituitary and it leads to the release of TSH ( Thyroid Stimulating Hormone ).

TSH is the typical hormone level that is being measured in people to determine whether they have a thyroid dysfunction or not. This TSH goes to the thyroid gland and the gland releases T4 hormone. This T4 needs to be converted to T3 which is the active form of thyroid hormone that works in the cells.

There is also an alternative pathway where the T4 is converted to Reverse T3 which works against the T3. So if T3 is the accelerator then Reverse T3 is the brake. 

As you can see above, there are so many steps that are involved in the production of thyroid hormone. If there is any problem in any of these steps then it can cause dysfunction. 

Thyroid Disease Symptoms with Normal Thyroid Test Results. 

The conventional way of determining thyroid dysfunction is measuring TSH. But with just one thyroid hormone level being checked we miss the chance of complete evaluation of thyroid.

And thus thyroid dysfunction often goes unnoticed and that’s the reason people have suffered for several years before finally someone checks their thyroid completely and discovers the underlying cause of the problem. 

Below I am going to talk about the reasons why are maybe experiencing thyroid disease symptoms with normal thyroid test results.  your thyroid tests might be normal but why are you still feeling the symptoms: 

1. Missed Hashimoto’s Disease

This is the most common form of thyroid illness which is missed.

The reason being Hashimoto’s disease is an autoimmune condition where slowly and slowly your thyroid tissue gets destroyed. Now if you are only checking TSH you will be missing early diagnosis of Hashimoto’s disease.

Hence, it is very important to check for thyroid antibodies called anti-thyroid peroxidase (anti-TPO) and antithyroglobulin (anti-Tg ).

So many females have thyroid symptoms and their Hashimoto’s antibodies have never been checked. They have had several TSh blood tests but never a complete panel and thus missing the diagnosis of Hashimoto’s.

These females suffer from symptoms for years without any explanation while we now know that this Hashimoto’s can be the reason for their symptoms. The reason being at this point of time conventional medicine doesn’t have a way to help people with Hashimoto’s disease except for giving thyroid hormone replacement. But in Functional medicine, we are all about prevention and treatment.

So if we can identify people with Hashimoto’s disease we can help reverse it or control it to the point that their antibodies and inflammation will decrease and at the same time symptoms improve significantly. 

2. Low T3 Syndrome

This is classically called sick thyroid syndrome, where during acute illness patients T3 levels go low. There are other changes in thyroid hormone levels in this condition but the majority of these patients will have Low T3 hormone levels.

This condition is typically seen in patients with poor nutrition/starvation, sepsis, burns, malignancy, myocardial infarction, post-surgery, and chronic liver and renal disease. But a lot of my chronically sick patients have some form of this presentation where the level of T3 is low while other markers are fine.

Other reason for low T3, is the poor conversion of T4 hormones to T3. This happens peripherally in GI tract and also in cell membranes. Inflammation in your body especially in the GI tract can interfere with this conversion and can lead to low levels of active T3 hormone levels.

So again if you don’t check all thyroid hormone levels you will never know if your T3 is chronically low and will not be able to take relevant actions to improve the underlying reason for this abnormality. 

3. Mitochondrial Dysfunction

Most of the symptoms that are part of thyroid dysfunction actually happen because of underlying mitochondrial dysfunction.

Especially fatigue, brain fog, mood changes, pain, weight issues, and gut dysfunction now are known to have roots in mitochondrial dysfunction.

Unfortunately, we still don’t have the perfect test to check for mitochondrial dysfunction, but there are tests that can give us indirect measures of mitochondrial dysfunction by measuring intermediate metabolites.

This is a huge research topic currently and the pharmaceutical industry is trying to make medicines to help with mitochondrial dysfunction. With a functional medicine approach,we dig deeper into why the mitochondrial dysfunction is happening and then take relevant actions to improve it.

I have seen so many patients with thyroid illness like symptoms which were actually mitochondrial dysfunction and after our protocols,they got better. 

Related Read : Program to fix Brain Fog From Thyroid Dysfunction.

4. Drugs That Affect Thyroid Function Tests

Several drugs and medications can interfere with thyroid hormone productions and levels in the body.

So when we are ordering tests and even treating people with those medications we need to have a high index of suspicion for thyroid abnormality because of medications.

Typical medications associated with drugs that affect thyroid function tests are Amiodarone, Lithium, dopamine agonists, steroids, metformin.

So if you are taking any one of these medications that can explain some of your symptoms but the test results might not be showing thyroid abnormality. 

5. Thyroid Hormone Resistance and Also disorder of thyroid hormone transport or metabolism

These are conditions that are rare and very difficult to diagnose properly. In these conditions sometimes because of genetic variation your body might become resistant to thyroid hormone. This is similar to what we see in Type II Diabetes where the body becomes resistant to the lin hormone.

The second condition is where there is a problem with either too high levels of thyroid binding protein or low levels of thyroid-binding protein. The thyroid hormone in the bloodstream is present in the bound form. Thyroid hormone is bound to thyroid binding protein, so if there is a significant difference in the levels of these thyroid-binding proteins it can interfere with optimal levels. Some of this condition is attributable to high cortisol levels and also is estrogen levels ( females on birth control pills for a long time).  

Summary –

So as you see that there are so many situations that can be the reason for you having all the symptoms of thyroid but you have been told multiple times that your thyroid tests are normal. Most often the reason is incomplete evaluation of thyroid dysfunction. By not ordering all the tests that are needed. But there are other situations that are not so common but are relevant for a lot of patients specially taking medications or lifestyle which can cause underlying dysfunctions leading to those symptoms.

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Related Read:

The 3 Step Program to Improve Brain Fog because of Thyroid Disorder

Zinc Supplement For Thyroid Health.

4 Toxins in Household Things that may be hurting your Thyroid

Are these Supplements Hurting your Thyroid?

Can I take Levothyroxine with Coffee in the Morning?

References :

Olympia Koulouri,Pitfalls in the measurement and interpretation of thyroid function tests. Best Pract Res Clin Endocrinol Metab. 2013 Dec; 27(6): 745–762.

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Tahboub R., Arafah B.M. Sex steroids and the thyroid. Best Practice & Research Clinical Endocrinology & Metabolism. 2009;23:769–780

Gurnell M., Visser T., Beck-Peccoz P. Resistance to thyroid hormone. In: Jameson J.L., De Groot L.J., editors. Endocrinology. 6th ed. Saunders Elsevier; Philadelphia, PA: 2010. pp. 1745–1759.

 Barkoff M.S., Kocherginsky M., Anselmo J. Autoimmunity in patients with resistance to thyroid hormone. Journal of Clinical Endocrinology and Metabolism. 2010;95:3189–3193