Hypothyroidism is a very common hormonal deficiency where there is an insufficient amount of thyroid hormone, T4. The thyroid gland regulates your metabolic activity. If you have insufficient thyroid hormone, everything seems to slow down; Your energy level, your muscle strength, your heart rate, your brain activity, and even your intestinal activity are all slower.
One of my habits in practice was to check the size of the thyroid, which is an H shaped gland astride the windpipe beneath the voice box. It becomes enlarged in a condition known as Hashimoto’s thyroiditis, the most common cause of adult hypothyroidism.
As you recall from the last posting, when the thyroid function is low, the brain causes a release of TSH, which stimulates the thyroid gland. In order to produce more thyroid hormone, the gland enlarges and the examining physician can feel it.
Babies can be born without a thyroid. I had one such patient when I was in training. The baby was inexplicably limp, and did not cry vigorously like other babies. When given thyroid hormone, she developed normally. Such babies often go undetected, don’t grow and become mentally deficient.
The thyroid gland produces thyroxine, which is T4. In the tissues, the T4 is converted into the much more active T3. This is often the medication of choice in hypothyroidism. In giving thyroid Hormonal, the physician must adjust the dose, depending on the patients response. Only after a number of visits is the proper dose found.
Please refer to the Mayo clinic article on hypothyroidism. The use of the TSH as a blood test is also discussed.