So many women come to me feeling that they are hypothyroid, they will have read up on the symptoms, but they don’t actually know how the thyroid works so even if they get a doctor willing to do all the tests, they won’t understand the results and what the tests are looking for. So this post is for anyone wanting to understand what the heck their thyroid is and why it is so important to our health and well being.
Hopefully before you started reading this your spotted the diagram above and found your thyroid, but the other major players you need to look for are your hypothalamus, pituitary and pineal glands. You also need to be familiar with your ovaries too.
Let’s Walk Through The Thyroid Hormone Cycle
Your hypothalamus releases a hormone called Thyrotropin Releasing Hormone (TRH) which tells the pituitary to secrete Thyroid Stimulating Hormone (TSH).
Surprise, surprise, TSH stimulates the thyroid to produce thyroid hormones, mostly Thyroxine (T4) and some Triiodothyronine (T3) and tiny amounts of T1 and T2 (we don’t know much about these hormones yet).
First of all T4 has to get converted into the active form T3, this happens in the gut, liver, brain, skeletal muscle tissue and even the thyroid gland itself as well as other tissues and organs in the body. Spoiler Alert: optimal gut and liver health is essential for a healthy optimally performing thyroid system! This active form of T3 is then used in the body to make energy and control metabolism, which is pretty important.
To finish off the loop the thalamus and pituitary are constantly screening the body for thyroid hormone levels and increase/decrease TRH and TSH production in response.
So that is the main loop but there is also another thyroid feedback loop below:
Your thyroid is essential for your progesterone levels and your progesterone levels affect your thyroid performance. I talk about this in more detail in this blog post about your thyroid and your period.