Top 10 Thyroid Tests and How to Interpret them

Inside: Know various ways we can test your thyroid problems. Here is a list of the top 10 thyroid tests divided into 6 major categories and how to interpret them the right way.

If you are facing any of the symptoms related to Thyroid Disorder, the first thing you should do is to get yourself tested! Testing Thyroid Hormone Levels is the Primary Step that diagnoses the Thyroid Disorder and helps to get appropriate medication for the treatment. 

For general diagnosis of Thyroid Disease, conventional doctors generally check the TSH and T4 Levels where TSH is Thyroid Stimulating Hormone and T4 is the amount of thyroid hormone circulating in your blood. 

Thyroid testing and interpretation

Although only these two tests are not enough to know the actual condition of Thyroid Disorder. There is a complete test panel that should be followed to know the real stage as a full thyroid panel includes TSH, T4, T3, TPO and TG antibodies. 

Hence, here are the major categories of the Top 10 Thyroid Tests that are important to know all the necessary information about your Thyroid Disorder. 

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1) The Thyroid Screening Test

TSH Test, also known as the Thyroid Stimulating Hormone Test is a screening test for Thyroid Disorder. TSH is the pituitary hormone that responds to low/high amounts of circulating thyroid hormone. 

Due to elevated TSH, the TSH hormone senses low thyroid levels which results in a lack of Thyroid Hormones and is called Hypothyroid. Vice versa is true for Hyperthyroid conditions. 

TSH Test is used for monitoring the correct dose of medication which is prescribed to the Thyroid Patient.

Thyroid testing and interpretation

TSH Test Interpretation

TSH Test should be done early in the morning without medication as taking medicines before the test will suppress your TSH Levels and show as if you are overmedicated. The Optimal reference range of TSH levels is 0.5-2 μIU/mL. So, if the TSH level is low, you are suffering from Hyperthyroid and if TSH Level is High, you are suffering from Hypothyroid. One should take the test every 4-6 weeks when starting a medication and once the symptoms are stable, one can take the test after every 6 months. 

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2) Thyroid Hormone Level Test

T1, T2, T3, and T4 are the four main thyroid hormones out of which T3, also known as triiodothyronine is the main biologically active thyroid hormone that gives us beautiful hair, replenishes our energy and runs our metabolism. 

T4 is known as prohormone and is 300 percent less biologically active than T3. Thus, testing the T3 and T4 levels determines the active thyroid hormone circulating in the body. 

Generally, the common medication prescribed for Thyroid contains T4 (Thyroxine) which is then converted into the active T3 form in the body. But in some individuals, the body does not convert enough hormones in the active T3 form. Hence, it is necessary to check.

Thyroid Hormone Level Test Interpretation

To check that your body is converting T4 hormones into active T3 Hormones correctly, both the hormones should be in the optimal range. 

  • Optimal Range for T3 : 5-7 pmol/L
  • Optimal Range for T4 : 15-23 pmol/L

So, if the T4 is optimal but the T3 is out of the optimal range, it means that your body is not making enough active T3 Hormones from the T4.

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3) Thyroid Antibodies

In Thyroid Patients, many Thyroid Antibodies are detected as a body cannot recognize its own tissue as a part of itself and hence, consider Thyroid Gland as a Foreign Invader and keep it in a situation of under attack. 

This leads to an autoimmune condition. In many cases, Thyroid Antibodies are the first indication of Thyroid Disorder and it can be elevated years ago before a change in TSH is even detected. 

Hence, it may happen that you have a normal TSH, but Elevated Thyroid Antibodies working in the background to damage your Thyroid gland and you may not produce sufficient hormones in near future. 

In Hashimoto’s Patients, TPO (thyroid peroxidase antibodies) and TG (thyroglobulin antibodies) are the most common antibodies. 

Thyroid Antibodies cause many symptoms like depression, panic attacks, anxiety, miscarriage/infertility, carpal tunnel, hair loss, weight gain, fatigue/laziness, and hypochondria. Hence, Thyroid Antibodies should be checked for diagnostic purposes and monitored to track remission.

Thyroid testing and interpretation

Thyroid Antibodies Interpretation

  1. Thyroid antibodies above 500 IU/mL are considered a very aggressive case of Hashimoto’s
  2. Antibodies under 100 IU/mL indicate remission or a less aggressive case
  3. Antibodies under 35 IU/mL mean you no longer test for Hashimoto’s according to conventional medicine standards
  4. Antibodies under 2 IU/mL are optimal (scientists believe that there may be some antibodies present as part of a normal repair process)

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4) The Thyroid Ultrasound

At times, you might have thyroid disease but your TSH and antibodies don’t reflect it as there are no detectable alterations in your blood work. 

In this case, it is suggested that one should take a 10 mins, easy and intrusive test which uses sound waves to image the thyroid. It helps you detect the change in gland size and texture. 

The Thyroid Ultrasound Interpretation

It determines changes in thyroid size (shrunken or enlarged), tissue density and texture (rubbery), as well as nodules (abnormal growths), which are all characteristic changes found with Hashimoto’s. 

One should take at least one ultrasound, especially for women of childbearing age and if any nodules are found, an annual ultrasound test is recommended. 

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5) The Reverse T3 Test

To measure how much of the active free T3 hormone is able to bind at thyroid receptors, the Reverse T3 Test is required. In Stressful situations, RT3 is produced and binds to thyroid receptors, but turns them off instead of activating them. 

T4 is converted into T3, but in stressful conditions, T4 is converted into RT3 which is an inactive molecule without any physiological activity. RT3 Test is used to diagnose Poor conversion of T4 into T3. 

It also identifies the symptoms that are due to adrenal stress, instead of thyroid malfunction or autoimmunity.

Thyroid testing and interpretation

The Reverse T3 Test Interpretation

If RT3 levels are going up, it indicates that your body is reacting to a stressful situation. High rT3 due to stress has a snowball effect on hypothyroid symptoms. The optimal reference range of RT3 lies between 11-18 ng/dl. 

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6) Symptoms

If you are suffering from Thyroid, keeping a check on your symptoms is a test itself! Changes in symptoms reflect the change in thyroid hormone levels. So, know the related symptoms of hypothyroid and hyperthyroid and analyze them over time to keep a check on your thyroid hormone levels. 

Symptoms Interpretation

Prepare a list of symptoms you generally face and make a chart of them. Rate the severity of symptoms ranging from 1 to 10 each week and aim to lower the score by working on the root cause. 

Thyroid testing and interpretation

Once you have done all the tests, interpreting your lab reports by checking them with optimal reference ranges is the major task to analyse the health condition. You should also keep the records of the reports to evaluate the recovery progress. 

Also, lab reports are the major indicators for Medication Prescriptions and adjustments as it determines the dose of medication and the need to reduce or increase the dose depending on the thyroid levels.


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