The Key Lab Tests for Hashimoto’s – Brightening Care

I receive so many questions from my readers about which labs to get for Hashimoto’s and where to get them. Figuring out which tests you should do can be overwhelming because there’s quite a bit of information out there, and there are multiple tests that can give us an idea of our current thyroid function, as well as triggers that can reveal why the thyroid may be malfunctioning. I wrote this article in hope that it serves as a starting point to help you determine which lab tests will be most helpful for uncovering your triggers.

I highly recommend working with a Functional Medicine clinician on your thyroid journey. Functional Medicine is a medical specialty dedicated to preventing, finding, and treating underlying causes of chronic illness, rather than merely treating disease symptoms.

If you have a practitioner who is willing to work with you, that practitioner can order most of the tests listed here. If you don’t have a practitioner like this on your team, I’ve spent some time reaching out to various lab companies to set up specialized channels that will allow you to self-order your own labs at a discount. I’ll specify which tests are usually covered on insurance if you have a willing practitioner that can bill insurance, which tests can be self-ordered and then submitted to insurance, and which ones are usually an out-of-pocket expense that you may need to save for. (You can use Health Savings Accounts for most.)

In this article, I will go over the tests that I think are critical for finding the root cause(s) of your Hashimoto’s condition, including:

Thyroid testing
Nutritional testing
Adrenal testing
Gut health testing
Infections testing
Genetic testing

Comprehensive Thyroid Testing

Establishing a baseline for your thyroid health and testing on a regular basis is a crucial first step in monitoring your health and understanding how possible “root cause” triggers may be affecting you. If you haven’t had any of the following thyroid tests done in the last three months, I recommend having them done as soon as possible.

TSH Test

TSH is a pituitary hormone that responds to low and high amounts of circulating thyroid hormone. ^{^[1]} This lab test reveals elevated TSH in people who have advanced Hashimoto’s or primary hypothyroidism. However, levels of thyroid hormone can fluctuate, so this test can potentially be misleading. It’s important to note that some people with Hashimoto’s and central hypothyroidism might have a normal reading when tested. People with Graves’ disease generally have a low TSH. ^{^[2]}

You can often predict an eventual rise in TSH decades before it happens. Usually, there’s an elevation in thyroid peroxidase antibodies (TPO antibodies) and thyroglobulin antibodies (TGAb antibodies) before TSH goes up. ^{^[3]} Those with Graves’ disease or thyroid cancer can have elevated thyroid antibodies, including TPO, TGAb, and TSH receptor antibodies. ^{^[4]}

The TSH level considered “normal” has been skewed for years because the original data collected included elderly patients and people with compromised thyroid function. Although there is an updated range, many doctors have been slow to join in. This is why I encourage you to work with a functional medicine doctor that will treat you and not just your labs.

Functional medicine practitioners have further defined that normal reference ranges should be between 1 and 2 μIU/mL, for a healthy person not taking thyroid medications. Anecdotally, most patients feel best with a TSH between 0.5-2 μIU/mL.

The TSH test can be useful in optimizing thyroid function by ensuring the TSH levels stay within the optimal reference range while implementing lifestyle interventions and medication dosage changes.

Free T4 and Free T3 Tests

Doctors usually measure total T3 and T4, which can be misleading because T3/T4 hormones are often bound to different types of proteins and aren’t available for proper use in our body. ^{^[5]} T4 (thyroxine) and T3 (triiodothyronine) are the two main thyroid hormones. T4 is known as prohormone and is 300 percent less biologically active than T3. ^{^[6]} T3 is the main biologically active thyroid hormone that runs our metabolism and gives us beautiful hair and energy.

Most of the commonly prescribed thyroid medications, like Synthroid (levothyroxine), only contain T4 and need to be converted to T3 in the body. In theory, the T4 to T3 conversion works as it’s supposed to, but in reality, we may not always convert T4 to T3. Free T4 and Free T3 tests reveal the levels of available and free thyroid hormones that interact with thyroid receptors.

Some clinicians may only test for free T4, but free T3 is also important to test, as some individuals may not be converting the T4 to the active T3 hormone properly. Thus, people may have normal T4 levels, but low T3 levels.

Thyroid Peroxidase (TPO) and Thyroglobulin (Tg) Antibodies Tests

The TPOAb and TgAb tests measure the antibodies that are the markers of autoimmunity, letting us know that the immune system is launching an attack on the thyroid gland. ^{^[7]} Generally, the higher the thyroid peroxidase and thyroglobulin antibody numbers, the more aggressive the autoimmune attack is on the thyroid. However, not everyone will have antibodies. (Read more about how some people with Hashimoto’s may not have any antibodies.) While not everyone with Hashimoto’s will have these antibodies, those that do can use them as a gauge of how aggressive the attack is on their thyroid, and can track the antibodies over time to see if their current lifestyle interventions are working. A reduction in thyroid antibodies is usually an indication that their lifestyle changes are helping.

Thyroid Ultrasound

An ultrasound reveals what’s happening with your thyroid. It shows whether or not you have changes consistent with Hashimoto’s, which could be characterized by changes in blood flow to the thyroid gland, a shrunken or enlarged thyroid, or even a “rubbery” thyroid. ^{^[8]} If you have nodules present, then they need to be watched, and an ultrasound can spot tumors that need to be biopsied or examined. (You can read more about diagnosing thyroid cancer here.)

I recommend doing an ultrasound at least once in your lifetime. If there are issues that need monitoring, then it’s recommended to have the ultrasound done routinely, such as on an annual basis. If everything stays consistent with Hashimoto’s, you should probably have one done every five years. If you’re actively trying to regenerate thyroid tissue and are doing thyroid regeneration protocols (low level laser therapy is a promising approach), then every three months would suffice. An ultrasound will need to be ordered by your doctor.

Insurance Coverage/Interpretation: All of the thyroid tests listed above should be covered on insurance, if the practitioner who orders them is an MD, DO, PA or NP. You also have self-order options. I love the independent lab network Ulta Lab because you can self-order the labs, and later submit them to your insurance for reimbursement. (Be sure to check with your individual insurance to make sure they allow this.) This is also a wonderful option for people with a high deductible. While it’s always best to work with a practitioner for an interpretation of these labs (especially if you need a prescription), I’ve also written a comprehensive interpretation guide for your reference.

For a full guide on interpreting your thyroid tests, please see my article: Top 10 Thyroid Tests and How to Interpret Them.

Nutritional Testing

People with Hashimoto’s and thyroid disorders are at a greater risk for nutrient depletions. ^{^[9]}

Nutritional deficiencies are a two way street. Nutrient deficiencies (especially abnormal ferritin levels) can contribute to thyroid symptoms and can even trigger or exacerbate thyroid disease, while thyroid disorders can lead to nutrient depletions. ^{^[10]} Thyroid hormones determine our metabolism throughout the entire body. As such, the digestive tract is not spared, particularly the intestines. An insufficient amount of thyroid hormones makes nutrient extraction more difficult and less efficient, and can in itself lead to nutrient deficiencies. ^{^[11]}

Additionally, most people with thyroid conditions will have low stomach acid (hydrochloric acid, or HCl), which is necessary to break down protein. ^{^[12]} This can lead to a depletion of amino acids, B vitamins, iron, zinc, and other nutrients obtained from protein. ^{^[13]}

This is why I recommend testing for a few key nutrients that are vital to thyroid health.

Root Cause Nutrition Panel

The Root Cause Nutrition Panel tests for B12, ferritin, vitamin D, CMP and CBC levels:

B12 is often lacking in Hashimoto’s, and supplementation is needed because a deficiency can result in neuropathy, fatigue, or problems with digestion. ^{^[14]} Optimal B12 levels should be between 700-900 pg/mL.
Ferritin is an important protein because it stores iron. If you’re deficient in it, then you probably have symptoms like hair loss, fatigue, and poor thyroid function. ^{^[15]} The optimal ferritin level for thyroid function is between 90-110 ng/mL.
Vitamin D is a major player in immune system balance. ^{^[16]} Hashimoto’s patients often have very low vitamin D ranges, and most of my clients who have gotten into remission have optimal levels of this nutrient. ^{^[17]} Vitamin D levels should be between 60 and 80 ng/L for optimal thyroid receptor and immune system function.
The CMP (complete metabolic panel) and CBC (complete blood count) will reveal your electrolyte levels, as well as how your cells are doing, how the liver and kidneys are functioning, and whether you are at risk for anemia. The results typically come back “normal” for most people with Hashimoto’s, but it’s important to have these done to rule out serious situations that may require urgent medical interventions.

Insurance Coverage/Interpretation: All of the nutrition tests listed above should be covered on insurance, if the practitioner who orders them is an MD, DO, PA or NP. You also have self-order options. I love the Ulta Lab Tests network because you can self-order the labs, and later submit them to your insurance for reimbursement. (Be sure to check with your individual insurance to make sure they allow this.) This is also a wonderful option for people with a high deductible. While it’s always best to work with a practitioner for interpretation, I do have protocols for how to address these deficiencies in Hashimoto’s Protocol, as well as a comprehensive article on the most common nutrient deficiencies in those with Hashimoto’s.

Adrenal Testing

In my experience, nine out of ten people with Hashimoto’s will be affected by adrenal dysfunction. Treating hypothyroidism without treating the adrenals is one of the biggest reasons people continue to feel exhausted despite receiving treatment with thyroid hormones.

The adrenal glands release hormones such as cortisol and adrenaline. These “stress hormones” impact many important functions throughout the body. They help establish our stress tolerance, tame inflammation, regulate blood sugar and body fat, control potassium and sodium levels (which impact blood sugar), and influence sex drive and anti-aging. ^{^[18]}

There are a few potential patterns of adrenal dysfunction that include low cortisol levels all day, elevated cortisol levels, and a flipped curve, meaning cortisol is high when it should be low and vice versa.

In analyzing 148 adrenal saliva tests of symptomatic people with Hashimoto’s from 2015 to 2019, I have noticed that all of the individuals tested had some degree of adrenal dysfunction.

While seven out of 148 tested individuals showed an excess of cortisol, 91 individuals had low levels of cortisol. Furthermore, in analyzing the 50 people whose cortisol was in the “normal range,” I noticed that their cortisol curve was off, they were producing either too little cortisol in the morning, they had fluctuations at their noon/afternoon readings, or they produced too much at night, which led to morning fatigue, midday mood swings, and/or trouble sleeping at night.