Chronic Lymphocytic Thyroiditis (Hashimoto's Disease)
Hashimoto's disease appears to be an inherited condition. As with
Graves' disease, you probably must inherit a gene or set of genes
to be able to develop this disorder. However, even though you may
inherit this genetic tendency, you still may never actually develop
the disease itself. Therefore, there must be other factors which
cause this condition to develop.
These other factors include being a woman, your age, and your body's
immune system. Thus, women are affected about eight times more often
than men, and although you may develop this form of thyroiditis
in childhood or adolescence, it is most commonly diagnosed after
the age of forty, for this is when affected patients usually become
hypothyroid. Your body's immune system plays a role in the production
of the thyroid inflammation and tissue destruction that occurs in
chronic lymphocytic thyroiditis. Substances known as autoantibodies,
made by white blood cells called lymphocytes, appear in your blood
in this condition. Although we do not yet fully understand how or
why these lymphocytes and antibodies work, the final result is damage
to thyroid tissue. When enough tissue has been destroyed, your thyroid
hormone production falls below normal, and symptoms of hypothyroidism
appear.
The most sensitive test for hypothyroidism is a blood test that
measures the level of the pituitary's thyroid stimulating hormone
(TSH ). When TSH tests are carried out on large numbers of people,
we find that about 10 percent of women and 4 percent of men over
the age of fifty have an elevated blood level of TSH. By age sixty,
TSH is increased in as many as 16.9 percent of women and 8.2 percent
of men. Put another way, at least one woman in six and one man in
12 will develop Hashimoto's disease in their lifetime. Each could
potentially develop subsequent hypothyroidism and should be watched
for signs of thyroid failure.
If you develop this condition, your thyroid inflammation will probably
be so mild that at first you won't even know that anything is wrong.
The first indication of a problem may be a goiter : You may develop
a gradual painless enlargement of your thyroid gland. During this
period, your thyroid gland is becoming infiltrated with lymphocytes,
which start gradual thyroid destruction and scarring that may result
in subsequent thyroid failure.
When hypothyroidism occurs, you probably will feel sluggish and
run down, but the disease progresses slowly, so you may not realize
that anything is wrong. Constipation, leg cramps, hair loss and
mental dullness may appear, together with other symptoms and signs
of thyroid failure. However, since chronic lymphocytic thyroiditis
tends to be a progressive condition, your thyroid hormone level
will probably continue to fall, causing your symptoms of hypothyroidism
to worsen until your disease is recognized and treated.
Your physician can confirm the presence of hypothyroidism by means
of a blood test that shows a low level of thyroid hormone (T4 )
and a high blood level of thyroid stimulating hormone (TSH). The
elevated TSH level is the more important test, for it is more sensitive
and proves that your thyroid, not your pituitary, has failed. Also,
a blood test demonstrating the presence of antithyroid antibodies
provides strong evidence of thyroiditis.
Since this condition may be progressive, lifelong follow-up is
essential, but this usually amounts to no more than your physician
examining your thyroid and testing your blood levels of T4 and TSH
at your annual health checkup. As your thyroid gland's function
declines, your thyroid hormone dosage may be increased appropriately.
On the other hand, the dosage may actually decrease in some elderly
persons.
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