Thyroid conditions are extremely common and some studies predict that 1 in every 20 people living in the US will experience a thyroid disorder at some stage in their life. There can be a lot of inconsistencies when it comes to diagnosing a thyroid disorder, as symptom presentation and pathology reference ranges can vary greatly. Here, I will be diving into what the thyroid does in the body and where is can go wrong.
This is the butter-fly shaped gland located in the front of the mid-neck. The thyroid influences many different functions in the body including metabolism, stress response, mood regulation, fertility, muscle function and digestion. The thyroid makes thyroxine (T4) and in lesser amounts, triiodothyronine (T3). It is regulated by both the hypothalamic-pituitary-thyroid axis (HPT) and the hypothalamic-pituitary-adrenal axis (HPA). Through a feedback system in the body, the anterior pituitary gland secretes thyroid stimulating hormone (TSH) when the thyroid needs to make more hormones (T4/T3) to increase various functions in the body.
It is important to note that T4 is mostly inactive in the body and needs to be converted to T3 in order to carry out its functions.
Where It Can Go Wrong
There are many different factors that can contribute to the development of thyroid dysfunction resulting in hypothyroidism (underactive), Hashimoto’s (auto-immune driven underactive thyroid), hyperthyroidism (over-active), and Grave’s disease (auto-immune driven overactive thyroid).
Hyperthyroidism and Grave's Disease
Hyperthyroidism can be caused by an auto-immune response (Graves's disease) in which the immune system attacks the thyroid gland causing it to secrete excess hormones. This is the most common cause of hyperthyroidism, but is not always the case.
Factors that can contribute to the development of Hyperthyroidism and Graves disease includes...
Hormone fluctuation in pregnancy
Excess iodine intake
Overactive thyroid nodules
Poor gut/liver health and Endocrine disrupting chemicals.
Symptoms can include but are not limited to:
Vision disturbances and bulging eyes
Specific Things to Note for Testing
Hyperthyroidism is diagnosed by a blood test showing low TSH, High free T4 and/or High free T3. The autoimmunity or Grave's disease is diagnosed by having TSH receptor antibodies present. Having a full thyroid panel conducted is important to understand exactly what is going on in the body.
Often times initial tests only include TSH, which is not an accurate representation of thyroid function. Ideally testing will include TSH, Free T4/T3, Reverse T3 and Thyroid antibodies (TPOAD, TgAb, TRAb). Blood tests should be conducted on a 10 hour fast, but no more than 12 hours with no strenuous exercise the day before. Thyroid ultrasounds may also be conducted to check for enlarged nodules impacting thyroid function.