Thyroid at Root of Many Symptoms
WebMD News Archive
Art of Testing
Shomon urges women not to drag (or rev) around feeling bad but
to consult a doctor. Probably the first test that will be done is a TSH test
for thyroid stimulating hormone, a substance produced by the pituitary gland
that regulates the thyroid gland. If the TSH is greater than the upper level of
normal (4.5 to 5 mU/L), many doctors will check the "free" T4 level
(thyroxin), which costs less than a T4 index, which tests both T3 and T4. A TSH
above 2 can mean fertility is impaired, Vliet says.
Kenneth R. Blanchard, MD, an endocrinologist in Newton, Mass.,
says what he learned in medical school -- to test only TSH -- was flat wrong.
He always tests for T3 and T4. "I have seen people living in misery with
100% T4," he emphasizes. Vliet also tests for T3 and T4, as well as
antibodies that can cause autoimmune problems. "You can have shortages of
T3 and T4 before the TSH goes up or down," she says. "Women with
significantly elevated antibodies may need medication before the TSH reaches 4
"We're patients, not lab values" is Shomon's motto. She
says the range of "bad" test results is too small and that doctors will
dismiss the same set of symptoms in one woman as hypochondria if the test
readings are a few tenths of a point lower than in another woman with the same
complaints. Vliet and Blanchard specialize in nailing down and treating thyroid
dysfunction at varying levels for each woman.
Treatment of both hypo- and hyperthyroidism is not totally
benign. A careful diagnosis is important.
Hypothyroid is an underproduction of thyroxin, so levothyroxine
sodium (Synthroid, Levoxyl) is given. "They used to tell you one pill a day
and you'll be fine," Shomon says. Now, she and Blanchard recommend giving
T3. "In a low dose," Vliet says. "High-dose T3 can cause heart
As for treating hyperthyroidism, radioactive iodine is
sometimes used or the gland is surgically removed. Treating hyperthyroidism is
tricky. Vliet herself immediately defers to an endocrinologist.
Shomon urges baseline testing for women at 35, as well as at
least a TSH test before getting pregnant, four months postpartum, and before
starting on antidepressants or hormone replacement therapy. "If your HMO
won't cover the test, you can get an FDA-approved home test." With the
fine-tuning required with this delicate gland, however, a doctor's supervision
is highly recommended.
Star Lawrence is a medical journalist based in