Monday, February 2, 2015

Hashimoto's Disease: Working to Understand my Diagnosis

The thyroid gland
Late last year I discovered I had developed a goiter. For those who don't know, a goiter is an enlargement of the thyroid gland, often becoming a visible bulge at the lower part of the front of the neck. It scared me a bit. This was a combination of me thinking about the neck being a sensitive area and my mind immediately jumping to lump = bad. It kept getting bigger, and right now I can feel it when I swallow. After testing, I showed clearly elevated thyroid auto-antibodies. After a lot of poking, prodding, blood tests, and questions I was told it was pretty definitive that I had Hashimoto's disease: an autoimmune disorder also known as chronic lymphocytic thyroiditis. I am now in the very early stages of treatment using levothyroxine, a synthetic thyroid hormone.

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
The thyroid is one of many glands that make up the endocrine system, which is a complex of hormone-secreting organs that control major aspects of normal body function. The endocrine system controls a body's development from child to adult. It keeps levels of certain substances, like insulin and calcium, in balance. It helps regulate your sleeping patterns. It also controls your metabolism and body temperature. The thyroid is involved in those last two. For proper function, the thyroid requires iodine as both thyroxine (T4) and triiodothyronine (T3)--two hormones produced by the gland--contain iodine. Consuming too much or too little iodine can exacerbate existing thyroid problems, or even cause them under certain circumstances.

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
In my case, I'm honestly not quite sure whether I've been having symptoms for an extended period of time. I gained some weight after some setbacks kept me from exercising as much as I had been and since then I've had difficulty losing even a single pound. Over the past few years it has seemed like I've been more tired, feeling less and less able to be as productive as I once was. My iron levels tend to be low, so I usually would chalk it up to needing more iron in my diet again. Now I can't help but wonder if it's been more complicated than that. My feet tend to not retain heat well, but I don't know if that is just the nature of my circulation or if it was an early sign of Hashimoto's. Lately I've definitely noticed how cold I've been feeling. One day my feet were so cold I lost feeling my toes and, after checking my thermostat, I was startled to discover it was 70°F inside. That is pretty definitively not normal. I've also been very tired, on more than one occasion sleeping through most of the day. I've actually woken up, gone to work, come home, and almost immediately fallen asleep again on more occasions than I care to count. With how much this has interfered with things, this is the biggest symptom I want to stop.

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 ServiceUniversity of Maryland Center for Diabetes and EndocrinologyAmerican Medical AssociationColorado 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. 

Friday, December 12, 2014

Name that...Animal!

Hint: it is NOT a lizard.

Image is from Wikimedia Commons under a Creative Commons license
Click "read more" to find out the answer!