“Every cell in the body has receptor sites for thyroid hormones. Thyroid hormones are responsible for the basal metabolic rate.  Lack of ideal thyroid hormone leads to a decline in cellular function of all body systems.  The thyroid is the central gear in the complex web of metabolism and is extremely sensitive to minor imbalances in all other areas of the body”  

Datis Kharrazian


The Thyroid Gland is located in the front (anterior) part of the neck. It is a part of the endocrine system and is often described as a butterfly in shape. The thyroid gland is controlled by the pituitary gland located at the base of the brain. The pituitary gland is regulated by the Hypothalamus.  The Hypothalamus is part of the brain and produces Thyroid Releasing Hormone (TRH).  The hormone TRH tells the pituitary gland to stimulate the thyroid gland to release Thyroid Stimulating Hormone (TSH) . The cells that make up the thyroid are able to absorb iodine.  These cells combine iodine and tyrosine to make T3 and T4 hormones which are released into the blood stream. For example, T4 regulates your heart rate, how fast your intestines process food, and control metabolism just to name a few.  When the level of thyroid hormones (T3 and T4) drop too low, the pituitary gland produces Thyroid Stimulating Hormone (TSH)  which stimulates the thyroid gland to produce more hormones.  As the thyroid hormone levels rise the pituitary responds by decreasing TSH.  Most of the thyroid hormones in the blood are attached to a protein called Thyroid Binding Globulin (TBG).  If there is an excess or deficiency of this protein it alters the T4 and T3 measurement but does not affect the ACTION of the hormone.  T4 represents 93% of the thyroid hormone produced by the gland.  The other 7%  is T3. Measurements of both hormones provides an accurate evaluation of thyroid function.

The thyroid gland is very sensitive to imbalances in physiological systems.  The thyroid gland is the most common site for autoimmune attack and oftentimes  the first sign of the development of autoimmune diseases.  Hashimoto’s disease is considered the most prevalent autoimmune disorder in the United States.  One study has found that up to 7-8% of the U.S. population have antibodies against their thyroid.  Thyroid antibodies have been found to be a marker for future thyroid dysfunction.

The thyroid gland is also very vulnerable to imbalances of the endocrine system.  Hormones, such as estrogens, progesterone, cortisol, and testosterone, have a major influence on thyroid imbalances.

The thyroid gland is very vulnerable to environmental disruptors, such as arsenic, nitrates, pesticides , etc; some known and many unknown.  The thyroid gland is vulnerable to many medications as well.

When all of this is taken into consideration there are many variables that can affect the function of the thyroid gland.  One tool for evaluating the function of the thyroid gland is through Serum Laboratory Tests.  This is the most effective way for a practitioner to identify and assess metabolic defects. Following is a list of the major markers used in assessing thyroid metabolism.

Thyroid-Stimulating Hormone (TSH) also called thyrotropin

This hormone is released by the pituitary gland after the hypothalamus releases TRH. When the level of thyroid hormone (T4) drop too low, the pituitary gland produces Thyroid Stimulating Hormone (TSH)  which stimulates the thyroid gland to produce more hormones.  As the thyroid hormone levels rise the pituitary responds by decreasing TSH. This is the most common marker used to assess thyroid function and is also the most sensitive. This is the only test performed in the traditional healthcare model as a means to screen a patient for thyroid disorders.  A TSH test alone does not consider the thyroid pituitary feedback loops, peripheral thyroid metabolism, or potential or active risk factors as identified by antibody testing.

Total Thyroxine (Total T4)

This test  measures both bound and unbound thyroxine levels; therefore, it does not give the activity of T4 when measured alone.  This test is best completed with a T3 Uptake to demonstrate a level of T4 activity.

Free Thyroxine Index (FTI)

This test determines the amount of active T4 available.

Free Thyroxine (Free T4)

This test is used to measure the amount of free or active T4 in the blood.

Total Triiododthyronine (Total T3)

This test is used to measure the total T3 concentration in the blood

Resin T3 Uptake

This test measures the amount of sites for active (unbound) T3 to bind on Thyroxine-binding proteins.

Free Triiodothyronine (Free T3)

This test measures the free T3 hormones levels.  The Free T3 test is the best marker to see what amount of active thyroid hormones are available for the thyroid cell receptor sites.

Reverse T3

The production of reverse T3 typically takes place in cases of extreme stress, such as major trauma.

Thyroid-Binding Globulin

Thyroid-Binding Globulin (TBG) binds thyroid hormones in circulation. It is the main protein responsible for carrying both T4 and T3 in the bloodstream.

Thyroid Antibodies

Thyroid autoantibodies indicate that the body’s immune system is attacking itself.  Thyroid Peroxidase Antibody (TPO Ab) is the most commonly elevated antibody in the autoimmune thyroid response

Whereas the medical model primarily looks at TSH and T4, functional medicine recognizes the importance of looking at all thyroid markers.  This approach provides the practitioner a better understanding of the overall function of the thyroid and body systems as a whole.

If you or someone you know have been under traditional medical care and are still experiencing symptoms of thyroid dysfunction, a functional medicine evaluation could be a beneficial next step

What is Next? 

Schedule an appointment with one of our practitioners who will be able to assist you to identify the root cause of your condition and provide the support needed for your body to heal itself. Thrive for Life provides a holistic approach to the care of our patients. We offer Chiropractic Care, Functional Medicine/Nutrition, Acupuncture and Massage Therapy. We have the ability to order testing and recommend nutritional and supplemental support for your condition(s).

For more information on how we can help, contact Barbara our Nurse Practice Manager, 314-395-4934 or barbara@tflchiro.com