year to establish the most effective DOSE, during
which time the doctor will routinely measure the
thyroid hormones in the blood and compare them
with changes in symptoms and the overall clinical
picture. Most people experience a vast improve-
ment within a month of beginning hormone
therapy. Treatment is lifelong. Undertreated or
untreated hypothyroidism results in progressively
worsening symptoms that can culminate in per-
manent damage to the cardiovascular and neuro-
logic systems. People over age 60 typically need
lower doses of thyroid hormone supplement for
therapeutic results.
Risk Factors and Preventive Measures
The key risk factors for hypothyroidism are being
female and age over 60; being both female and
over 60 in combination increases the risk because
of estrogen’s role in hormone balance. People who
have received RADIATION THERAPYto the lower face,
neck, or upper chest have increased risk for
hypothyroidism. Lithium, a medication taken for
BIPOLAR DISORDER, may disrupt thyroid function
and cause hypothyroidism. There are no measures
to prevent hypothyroidism.
See also AUTOIMMUNE DISORDERS; CALCITONIN;
ESTROGENS; EUTHYROID SICK SYNDROME.hypothyroidism 147