Thyroid Blood Tests: All you need to know

Have you been feeling tired or lethargic and put on some weight? It might not just mean you are lazy. It could indicate that your thyroid gland is not as active as it should be. In this case, your doctor would advise you to get a thyroid panel or thyroid function test done. The main components of this are serum Thyroid Stimulating Hormone (TSH), triiodothyronine (T3) and thyroxine (T4).
Thyroid blood test/

Let us see what these tests mean and how to interpret them. And how we at Jeevam Health go one step beyond to take better care of you.

How thyroid tests are performed?

Typically, fasting is not necessary for thyroid testing. Mornings are the best time for optimal assessment.
A blood sample is required which is drawn from a vein in your arm. One sharp prick is required. In experienced hands, the process is virtually painless and only takes a few seconds.

Who needs to get a thyroid test done?

The two main groups of people

  • Those having symptoms- The thyroid gland affects virtually every part of the body. Symptoms could be related to the heart, gut, immune system, bone, nervous system or reproductive organs in women.
  • Those diagnosed with thyroid disease who need monitoring.

Having a thyroid disease means your thyroid gland is producing either too much or too little of the hormones T3 and T4. These perform various vital functions in the body. Thyroid-Stimulating Hormone (TSH)/

Then what is TSH for? It is a hormone produced by the pituitary gland. It controls the function of the thyroid gland. The levels of TSH get affected earliest when there is any thyroid disease. This is why some doctors advise getting only TSH levels done.

This may, however, not be the best idea. TSH levels may be difficult to interpret and need to be considered in the context of clinical findings. Not only this, there has been much debate over what level should be considered a cutoff. Join Thyroid Community/

How thyroid tests are interpreted?

TSH levels are an indicator of level of activity of the thyroid gland. When the thyroid gland is not functioning optimally, T3 and T4 levels in the bloodstream are below normal levels. When this message is conveyed to the brain, it increases the stimulation to the thyroid gland. This results in an increase in levels of TSH, which will mediate this action. Hence, a level of TSH higher than normal indicates hypothyroidism.

A similar mechanism occurs in case of an overactive thyroid. Higher levels of T3 and T4 will cause a decrease in levels of TSH. Hence, a level of TSH lower than normal indicates hyperthyroidism. The most common forms of this are Graves' disease and thyroid nodules.  

Paramater Optimal Health Range Traditional Range
TSH 1.8-2.5 mIU/L 0.4-4.5 mIU/L
Total T4 6.0-11.9 mcg/DL 4.5-12 mcg/DL
Free T4 1.0-1.5 ng/DL 0.8-1.8 ng/DL
Total T3 90-168 ng/DL 76-181 ng/DL
Free T3 2.8-3.5 pg/mL 2.3-4.2 pg/mL

Traditionally, TSH levels from 0.4-4.5 mIU/L have been considered normal. Levels from 4.6-8.0 mIU/L suggest subclinical hypothyroidism. It is important to remember that these values cannot be considered absolute.

Many experts consider the cutoff for normal TSH levels to be 2.5 mIU/L. Patients with levels above 2.5 can have insulin resistance, higher blood pressure, elevated triglycerides and a higher body mass index. These increase the chances of metabolic syndrome, a major risk to your cardiovascular health. So, any level higher than 2.5 can put you at risk.

What does this mean?
Simply put, it means that a TSH level between 2.5 to 4.5 does not definitively mean that a patient does not have a thyroid disease. Therefore, always trust your doctor to evaluate the blood tests and your symptoms together. He can best assess what care you need going forward.

The same holds true for hyperthyroidism where TSH levels are typically below 0.4 mIU/L. However, scientific evidence suggests levels above 1.0 are optimal.

TSH levels can be affected by many factors, such as:

  • Taking other medications. Metformin, one of the most commonly prescribed treatments for diabetes, can also cause a false reduction in TSH levels.
  • Women who are pregnant or on birth control pills
  • Presence of other autoimmune diseases
  • Age and gender of the patient, levels being higher in older females
  • Taking biotin supplements
  • Time at which the test is done, levels being most accurate in the morning

The next set includes T3 tests and T4 test. T3 is the active form which performs all the biological actions in the body. Hence, for the body to function normally, T4 has to be converted to T3.

T3 circulates in the bloodstream, both bound and not bound to protein. The free (unbound) T3 is the only form which is able to enter and affect the body tissues. A total T3 test measures all the T3 in your body. This includes the inactive bound form as well. Free T3 a crucial test which only measures the amount of T3 which performs essential functions.

The conversion of T4 to T3 can also be affected by various factors such as:

  • Imbalance in gut microbiome
  • Stress
  • Improper liver function
  • Extreme calorie restriction

In these situations, TSH level may be normal as the feedback effect of thyroid hormones is maintained. Nevertheless, symptoms are present too as the hormone is not the active form.

Keeping all these factors in mind, it is suggested to go a little deeper to evaluate the root cause of thyroid illness.

Antibody testing for the thyroid gland

There are certain people who have thyroid problems but their TSH test, T3 levels and T4 levels are all normal. That is because the disease process acts beyond these test measures. Such a person may have elevated antibody levels. This may occur in early stages of disease.

There are two main antibodies implicated in the causation of hypothyroidism. These are:

  • Anti-thyroid peroxidase (anti-TPO)
  • Thyroglobulin Antibodies (TgAb)

Thyroid peroxidase is an enzyme required in the synthesis of T3 and T4. Antibodies against this directly hampers the ability of the thyroid gland to produce hormones. Presence of either one of these autoantibodies implies presence of autoimmune thyroid disease. This is known as Hashimoto's autoimmune hypothyroidism.

One factor to keep in mind is that thyroid disease does not develop abruptly. The disease process is gradual, which is why it is often missed by conventional blood tests. This is where the relevance of antibodies is highlighted.

Consider a person having symptoms of fatigue, weakness, dry skin and hair fall. Despite normal hormone levels, in the presence of antibodies, it means the person has a disease which the regular thyroid panel missed.

How to approach thyroid testing?

Standard protocols in India generally use serum TSH to screen for presence of thyroid disease. Only those with derangement are advised free T3 or T4 levels. This results in missing out of several cases.

Hence, our first step at Jeevam Health is to perform a complete profile, without cutting any corners. This includes testing for TSH, T3, T4, free T3, free T4, and thyroid antibodies.

A key component of our treatment approach is not just resolution of symptoms, but working towards treating the disease itself. We choose to adopt a personalised approach for optimal results. This helps us understand what are the specific factors in your history and lifestyle that can be modified. This includes:

  • Assessing micronutrient levels to address specific deficiencies
  • Identify the presence of goitrogens in your diet and eliminate them
  • Find the triggers such as stress present in your lifestyle pattern and manage them
  • Heal from within by restoring gut health
  • Detoxification with diets directed towards reducing inflammation
  • Hormone replacement therapy

Many nutrients such as iron, iodine, zinc , selenium, vitamin E and other B complex vitamins are needed for the thyroid gland to function. Stress and inflammation cause inactivation of T4 hormone such that it does not convert to T3.

Conversely, nutrients such as vitamin A and practices such as exercise can improve the response of the body to thyroid hormones. All of this means that the gland itself is only one part of the problem. Hence, a few additional tests are required to treat it best.

How knowing all of this can help you?

Thyroid disease does not occur in isolation. Much like other autoimmune diseases, it is an indicator of deep seated problems which need to be understood. Functional Medicine helps address these modifiable factors to identify the root cause. This means adopting a holistic approach to make you healthy from inside out. In the long term, this implies healing without relying only on medications and potentially reversing the disease itself.

We’re here to help. Please get in touch with us and we can help address your concerns and assist you in your journey to better health. Book a call with Jeevam Health Team NOW!

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