The thyroid gland |
The curious side of me, of course, wanted to know more. Especially as this is going to affect the rest of my life.
The endocrine system |
When it comes to maintaining levels of thyroid hormones, there is a feedback loop involving the thyroid, the pituitary gland, and the hypothalamus. It's a classic negative feedback loop. The hypothalamus produces thyroid releasing hormone (TRH), which then triggers the pituitary to release thyroid stimulating hormone (TSH). This then triggers the thyroid to produce T4 and T3. When levels of T4 and T3 in the blood reach a certain level, this then signals the hypothalamus and pituitary to stop releasing TRH and TSH, respectively. When testing to see if someone has a thyroid problems, looking at levels of TSH and T4 will generally tell the most about about what is going wrong. If someone has low TSH and high T4, it would indicate hyperthyroidism (over-activity of the thyroid gland). High TSH but low T4 would be due to hypothyroidism (under-activity of the thyroid gland).
In many ways, hypothyroidism and hyperthyroidism cause symptoms that are opposite of each other. Hyperthyroidism includes things like difficulty tolerating heat, sweating more, restlessness, anxiety, and weight loss. Hypothyroidism, on the other hand, has symptoms that involve difficulty tolerating the cold, depression, and weight gain. One speeds everything up while the other slows it all down. However, both ends of the spectrum will make you tired.
Hashimoto's disease is pretty typical of hypothyroidism, but with a few interesting caveats. As it's an autoimmune disorder, but a very specific one, it involves someone's own immune system attacking the thyroid gland. Over time, the thyroid is killed off. Hashimoto's tends to have a gradual onset because it takes time for the thyroid to be damaged to the point that it enlarges or a person starts experiencing noticeable symptoms. It can be years before someone is diagnosed, if they are diagnosed at all. There is also no cure, and the only current treatment is thyroid hormone replacement therapy.
My goiter |
The good thing? The medication does seem to be starting to help a bit. The doctor and I just need to work on dialing in the right dose.
Hashimoto's disease is diagnosed at a rate of three to fifteen per ten thousand people. It is the most common cause of hypothyroidism in the United States. There are two major risk factors: having a family history and being born female, with only one male being diagnosed for every twenty females. Looking at my family history, it's really not overly surprising that I have a thyroid problem. On my mother's side, my grandfather took synthetic thyroid hormones. On my father's side, I have two aunts with hypothyroidism of some sort and a cousin who I know has Hashimoto's. That's a lot of malfunctioning thyroids!
Sources are Johns Hopkins Medical Institutions Autoimmune Disease Research Center, National Endocrine and Metabolic Diseases Information Service, University of Maryland Center for Diabetes and Endocrinology, American Medical Association, Colorado State University, Medline Plus: Chronic thyroiditis (Hashimoto disease), Medline Plus: Hypothyroidism, Medline Plus: Hyperthyroidism. Images one and two are from Wikimedia Commons under Creative Commons licenses (one, two). The third image was taken by me.
Sources are Johns Hopkins Medical Institutions Autoimmune Disease Research Center, National Endocrine and Metabolic Diseases Information Service, University of Maryland Center for Diabetes and Endocrinology, American Medical Association, Colorado State University, Medline Plus: Chronic thyroiditis (Hashimoto disease), Medline Plus: Hypothyroidism, Medline Plus: Hyperthyroidism. Images one and two are from Wikimedia Commons under Creative Commons licenses (one, two). The third image was taken by me.