The thyroid uses a hormone as its foot on our metabolic gas pedal. The thyroid is a gland, or collection of tissue sharing one function, which secretes this hormone into our blood stream. The hormone travels throughout the body and interacts with receptors on cells. These cells respond by changing the rate of their cellular metabolism, and we feel the effects in terms of how fast different body functions work.
This is all controlled by another gland hanging down from our brain which is called the pituitary. This gland senses the levels of thyroid hormone, particularly T4, and secretes its own hormone called TSH, or thyroid stimulating hormone. The TSH travels through the blood stream and tells the thyroid gland how much hormone T4 to make and release. Besides responding to levels of T4 in the blood, the pituitary responds to signals from the brain to alter its preferred T4 set point.
Thyroid hormone is first produced, then stored in the gland’s tissue bound to a protein called thyroglobulin. When the TSH from the pituitary stimulates the thyroid, the thyroid hormone is cut off the thyroglobulin, and released into the blood. After traveling to the various body tissues as either T4 or T3, the two forms of the hormone to be discussed in a future article, either form binds to a receptor made just for it on the cells. This binding triggers reactions in the cells that change cells behavior.
The effects mainly determine the speed of various bodily functions through metabolism. Higher levels of hormone stimulate faster metabolism and faster functions. Excessively high levels could cause diarrhea, weight loss, anxiety, insomnia, and palpitations. Excessively low levels could result in constipation, fatigue, dry skin, depression, slow heart rate, and other symptoms. Both high and low levels can lead to hair loss. Both high and low levels can also have adverse effects on other hormones like cortisol and the reproductive hormones. That is a story for another blog article on another day.
Functional MD’s like myself address thyroid issues about as frequently as any other condition since it can play a role in so many other root causes dysfunctions. We must always ask ourselves if our patients might have thyroid dysfunction. Then when we find it, we must determine the best approach to both alleviating their symptoms and addressing root causes. These therapies will serve as the topic of a future blog article.
Tl;dr- Our thyroid gland makes two active forms of thyroid hormone. Too little hormone and metabolism slows. Too much hormone and things speed up too much. The speed of our metabolism affects us through a number of symptoms.
Sanctuary Functional Medicine, under the direction of Dr Eric Potter, IFMCP MD, provides functional medicine services to Nashville, Middle Tennessee and beyond. We frequently treat patients from Kentucky, Alabama, Mississippi, Georgia, Ohio, Indiana, and more... offering the hope of healthier more abundant lives to those with chronic illness.