A standard workup for my patients that I suspect have low thyroid function is much, much more comprehensive than most doctors. Here is what I include in my testing:
TSH – The most common marker used to assess thyroid function and the most sensitive. This hormone is released by the pituitary when it gets the signal from the hypothalamus. TSH levels increase when T4 levels drop, and TSH decreases when T4 levels are elevated. Sometimes this is the only marker your doctor will order.
Free T4 – This is the unbound version of T4. This marker can be influenced by thyroid hormone replacement, chronic illness, as well as disorders that affect the amount of carrier proteins.
Free T3 – The unbound form of T3. This is the best marker to see what amount of active thyroid hormone is available for the cells. This can be affected by stress, thyroid disorders, and pregnancy.
Reverse T3 – This version of T3 is metabolically inactive. Reverse T3 is only typically produced in cases of extreme stress such as surgery or trauma. Chronic stress can also cause the production of Reverse T3, thereby masking the adrenal issue and looking like a dysfunctional thyroid.
TPO Antibodies – Most common marker elevated with autoimmune thyroid. 90% of thyroid issues are autoimmune related. This marker is rarely tested since there is no pharmaceutical drug to fix the problem, only lifestyle.
Anti-thyroglobulin Antibodies – Not as commonly elevated with an autoimmune thyroid condition. During thyroid cancer treatment, this marker is routinely evaluated.
Thyroid Stimulating Immunoglobulin – These antibodies are elevated with an autoimmune thyroid condition called Grave’s disease. This marker indicates a hyperthyroid state. This marker might only be required if your doctor is suspecting Grave’s Disease. This is an overly active thyroid condition cause by autoimmunity.
If you have a hard time getting these markers run by your healthcare provider, please contact me to discuss your concerns in more detail. I am devoted to serving those in need of comprehensive thyroid care. You may not need all of these tests, but it is good to know that they are available for your doctor to evaluate.