It is important to distinguish this from Hyperthyroidism, which sounds much the same, but is just the opposite. In Hyperthyroidism, the thyroid gland is overly active, and producing too much thryoid hormone.
Quick note. Levothyroxine is now available via online order on Amazon:
Blood tests look at TSH levels, which are high in cases of hypothroidism like mine. This is counterintuitive until you get it straight in your mind that the TSH level is not the amount of thyroid hormone, but it is a signal to the thyroid gland to produce the hormone. Apparently it is more informative to test the TSH level than to test the levels of T3 or T4 (which is the thyroid hormone itself). When TSH levels are high, your body is sensing a need for more thyroid hormone and is signaling the thyroid gland to make more. Like pushing hard on the gas pedal when your cars engine is only running on 3 out of 6 cylinders. Your pituitary gland is what actually produces the TSH hormone that tells (or tries to tell) the thyroid gland how active to be.
For years my TSH levels were high, but I had no symptoms and my doctors and I agreed to just ignore the situation and keep an eye on it. Now that I have noted some symptoms (fatigue and cold sensitivity), I have begun taking supplemental thyroid. Some of the classic symptoms are:
As I understand it, the thyroid hormone is an all around control of the bodies metabolism. So, when there is not enough of it, you get tired, cold, and burn less fuel and hence may gain weight.
A whole different point of view (and endorsed by a certain endocrinologist) is to just take your meds with your coffee, get your levels tested, and let the dosage be adjusted to fit your routine. Some people (amazingly) make themselves slaves to the "hour before" recommendation, and set their alarm an hour early, get up and take their pill, then try to sleep for another hour. It has been suggested that getting a good nights sleep is probably more important than whatever benefit there is from optimum thyroid absorption.
I have found the following online resources to be very good:
Apart from treating the symptoms, I have wondered what else might be going on in my body that I am not aware of when I am not taking medication. I have read that an underactive thyroid can lead to high blood pressure and high cholesterol levels, which could lead to heart disease. Pregnant women might have issues that I don't need to worry about.
I am told that it takes a few weeks for medication to stabilize your thyroid levels. Levothyroxine has a half life of about 7 days, so after a week, about half the dose will still be in your blood. Too much of the stuff can lead to nervousness, an elevated heart rate, sensitivity to heat, osteoporosis -- so getting it right is what you want to do. Levothyroxine is T4 and your body converts it to T3 as needed. T3 has a much shorter half-life. Normal TSH is 0.5 to 4. Many people are happy to get into the upper part of this zone, but some doctors like to see you in the lower half (below 2.5), especially if your symptoms are not resolved with less medication. My philosophy is to use the least medication necessary - I don't want my thryoid gland to just shift into neutral.
Tom's health pages / tom@mmto.org