If you’ve been experiencing weight gain, fatigue, hair loss, difficulty sleeping, or anxiety, your healthcare provider may order a thyroid panel to check your thyroid hormone levels.
A thyroid panel is a series of tests used to check thyroid health. It’s common for healthcare providers to order a thyroid panel if they suspect thyroid autoimmunity or central hypothyroidism. Some providers will begin by only testing your thyroid-stimulating hormone (TSH) level, while others will immediately request a full thyroid panel.
There’s a lot of conflicting information available on thyroid disorders and testing, making it confusing to know which approach is best. In this article, we’ll cover what thyroid function tests are included in a thyroid panel and five conditions you can identify with a thyroid panel. We’ll also discuss the potential pitfalls of thyroid panel testing and simple ways you can treat thyroid disease.
What Is a Thyroid Panel?
Healthcare providers use thyroid panels to diagnose thyroid disorders and to monitor the effectiveness of thyroid medication.
A complete thyroid panel provides a more detailed picture than specific blood tests for TSH (thyroid-stimulating hormone) level  and typically includes screening for the following markers:
- TSH (thyroid-stimulating hormone) — a hormone produced by the pituitary gland to regulate thyroid hormone production
- Free T4 (thyroxine) — a thyroid hormone produced by the thyroid gland
- Free T3 (triiodothyronine) — a thyroid hormone produced in small amounts by the thyroid gland and also converted from Free T4
- TPO (thyroid peroxidase antibodies) — a thyroid antibody; elevated levels may be a marker of Hashimoto’s disease
- TG (thyroglobulin antibodies) — a thyroid antibody
- TRab (thyrotropin receptor antibodies) — thyroid antibody; elevated levels may be a marker of Grave’s disease
Some endocrinologists and healthcare providers may include additional tests like Total T4, Free T4 Index (FTI), Total T3, T3 uptake, and thyroid-binding globulin (TBG).
For common thyroid conditions like hypothyroidism and Hashimoto’s disease, we’ve seen complex testing protocol recommendations for the ongoing use of complete thyroid panels.
At Austin Center for Functional Medicine, we have found that a simpler approach can be very effective for the most common thyroid conditions:
- TSH and free T4 are all that’s needed to diagnose hypothyroidism and hyperthyroidism. TSH is normally a reliable indicator of the amount of thyroid hormone your body produces. We also test for T4 to check for subclinical hypothyroidism and central hypothyroidism.
- TPO antibodies are used to diagnose Hashimoto’s disease, a type of thyroid autoimmunity. Thyroid autoimmunity is a separate condition from hypothyroidism.
This simplified thyroid panel provides excellent results and can eliminate unnecessary testing. Most patients don’t need to monitor T3 levels and TG antibodies, as these are less reliable indicators of thyroid health. If you want to know why we don’t routinely monitor T3 levels (an approach that’s popular with some practitioners), please read on.
5 Conditions a Thyroid Panel Can Point To
Measuring thyroid-stimulating hormone (TSH) and thyroxine (Free T4) can accurately identify four thyroid conditions: hyperthyroidism, hypothyroidism, subclinical hypothyroidism, and central hypothyroidism. Thyroid antibody tests are used to diagnose thyroid autoimmune conditions.
Hyperthyroidism is diagnosed when you have low thyroid-stimulating hormone (TSH) levels combined with high free T4. A diagnosis of hyperthyroidism (overactive thyroid) means your thyroid gland produces excess thyroid hormone.
To protect against inaccurate test results, patients taking biotin supplements or B-complex should stop supplementation 2-3 days before thyroid tests. Supplementing with vitamin B7 (biotin) before thyroid blood tests can cause falsely high Total T3 and free T4 results, which may lead to misdiagnosis of hyperthyroidism .
Hypothyroidism is the most common thyroid disorder and is more prevalent in women than in men. Hypothyroidism is diagnosed when you have high thyroid-stimulating hormone (TSH) levels and low free T4 levels. A diagnosis of hypothyroidism means you have a thyroid hormone deficiency (underactive thyroid gland).
Hypothyroidism often co-occurs with autoimmune diseases, including Hashimoto’s thyroiditis, type 1 diabetes, and celiac disease .
3. Subclinical Hypothyroid
Subclinical hypothyroidism is diagnosed when your TSH concentrations are above the normal reference range, but free T4 levels are normal. Patients diagnosed with subclinical hypothyroid may not need to take thyroid hormone replacements, and in many cases are prescribed thyroid medication prematurely. In most subclinical hypothyroid cases, your thyroid hormone concentrations will return to normal (euthyroid), and treatment is not required .
4. Central Hypothyroid
Central hypothyroidism is rare and affects men and women equally. Central hypothyroidism is caused by pituitary gland dysfunction or congenital defects in the thyroid gland. If you have central hypothyroidism, your TSH levels are normal, but your free T4 levels are low.
5. Autoimmune Thyroid Disease
Autoimmune thyroid disease is diagnosed by testing the following thyroid antibodies:
- TPO (thyroid peroxidase antibodies)
- TG (thyroglobulin antibodies)
- TRab (thyrotropin receptor antibodies)
The most common autoimmune thyroid disease is Hashimoto’s thyroiditis. TPO measurements provide the most reliable measure for Hashimoto’s . Elevated TPO antibodies may indicate a patient has Hashimoto’s thyroiditis. A thyroid ultrasound can confirm this by checking for thyroid inflammation.
Elevated thyrotropin receptor antibodies (TRab) indicate a patient may have Graves’ disease, putting them at risk for hyperthyroidism . However, Grave’s disease is not as common as other thyroid disorders .
If left untreated, thyroid autoimmunity can damage the thyroid gland and lead to hyperthyroid and hypothyroid conditions , but this is not automatically true in all cases:
- Elevated TPO levels between 35 and 500 IU/mL indicate minimal risk of progression to hypothyroid or hyperthyroid .
- TPO levels above 500 IU/mL indicate moderate risk of progression to hypothyroid [9, 10].
If your TPO levels are above 500, attention to diet, lifestyle and gut health can often help to reduce antibody levels.
3 Cautions About Thyroid Panel Results
We see three very common problems in the diagnosis and treatment of thyroid conditions:
1. Overdiagnosis of Thyroid Conditions
Research shows that thyroid medication is commonly overprescribed. A study on thyroid medication found that 60% of 291 participants who paused their thyroid medication for 6-8 weeks saw their thyroid labs return to normal without further treatment or intervention .
If your thyroid panel results don’t show high TSH combined with low T4, you likely don’t meet the criteria for hypothyroidism and don’t need thyroid medication. If you have hypothyroid symptoms, poor gut health is a likely culprit.
2. Incorrect Treatment of Low T3
Low T3 is a condition associated with inflammation, chronic illness, and poor nutrition . Prescribing combination T4/T3 medication for low T3 levels may not be the best approach. Overprescribing T3 medication can be harmful and may lead to increased fatigue/tiredness, worsening mood, and impaired sleep. Instead, treating gut imbalances and nutritional deficiencies will likely provide more significant benefits for patients and research supports this approach [13, 14, 15].
3. Using Thyroid Medication to Treat Thyroid Autoimmunity
If your thyroid panel results suggest that you are hypothyroid, it’s important to take thyroid hormone replacement to return your thyroid hormone levels to the normal range.
However, thyroid hormone replacement does not resolve thyroid autoimmunity and thyroid inflammation. It also may not resolve all of your thyroid symptoms. For autoimmunity, inflammation, and symptoms that don’t resolve with standard medication, a gut healing protocol may be very helpful.
3-Step Approach to Treating Thyroid Conditions
At the clinic, we treat thyroid conditions with a three-step approach:
1. Take standard thyroid medication.
2. Use gut-healing therapies.
3. Retest thyroid hormone levels and adjust medication.
For a comprehensive look at the impact gut health can have on thyroid conditions, download our Gut-Thyroid Guide.
The Bottom Line
Thyroid patients who want to take charge of their thyroid health often feel overwhelmed by the volumes of conflicting information that can be found on the internet.
To help cut through the complexity and noise, a testing approach that focuses on the most clinically relevant markers can help. For most patients, thyroid panel testing only needs to include TSH, free T4, TPO antibodies.
Having a simple, stepwise treatment protocol can also be helpful. In this case, we recommend first using thyroid hormone replacement to balance thyroid hormone levels. An important next step that’s often overlooked — calm the immune system and reduce inflammation through diet and lifestyle changes and treating your gut health. Lastly, recheck thyroid hormone levels and adjust medication dosages as needed.
If you would like assistance improving your thyroid health, contact our office today.