iThei mdcdaelcinfd o c elllllrlllll tThe hlcinfd olsbdkpvouvthose causing an overabundance of thyroid hormone production
(hyperthyroidism).
Hypothyroidism
Common symptoms of hypothyroidism, or thyroid hormone defi-
ciency, include a slowed metabolism, weight gain, forgetfulness, feel-
ing cold or cold intolerance, depression, fatigue, dry skin, constipa-
tion, loss of ambition, hair loss, muscle cramps, stiffness, joint pain,
a loss of the outer third eyebrow, menstrual irregularities, infertility,
and weakness.
Iodine Deficiency Versus Hashimoto’s
When there is a deficiency in the building blocks required to make
thyroid hormone (iodide, selenium, zinc, and tyrosine), TSH is trig-
gered to signal additional production of TPO to start converting the
stored iodide to a usable form (this also results in hydrogen peroxide
production). If no iodide is available, the body will attempt to in-
crease thyroid hormone production by making bigger thyroid cells,
thus resulting in an enlarged thyroid gland known as a goiter.
Iodine deficiency is the leading cause of hypothyroidism in many
underdeveloped countries and can cause both hypothyroidism as
well as goiters.
In the United States and many European countries, however—where
iodine is added to salt or other foods—Hashimoto’s is the leading
cause of hypothyroidism, not iodine deficiency. Hashimoto’s is re-
sponsible for 90 percent of hypothyroidism cases in the US.
Additional causes of hypothyroidism include silent (or painless) thyroid-
itis and postpartum thyroiditis, both of which are associated with anti-
body production but resolve on their own with a normalization of thy-
roid antibodies and return to optimal thyroid function. In many cases,
however, these conditions may be followed years later by Hashimoto’s.
Silent thyroiditis has been associated with seasonal allergies, viral
infections, and vigorous neck massage. The trigger for postpartum
thyroiditis is pregnancy. Perhaps these two conditions are examples
of the beginning of an autoimmune response that becomes extin-
guished once the triggers are removed.1,2,3, 13