HORMONE, which draws calcium from the bones
into the blood to meet the calcium needs else-
where in the body.
Generally, disorders of the thyroid gland have
little effect on calcitonin synthesis because such
disorders affect the follicular cells. A notable
exception is an uncommon form of THYROID CANCER
called medullary carcinoma, which develops in
the parafollicular cells that synthesize calcitonin.
Elevated levels of calcitonin in the blood circula-
tion without corresponding parathyroid dysfunc-
tion raise the suspicion that such a cancer is
present.
COMMON DISORDERS OF THE THYROID GLAND
GOITER GRAVES’S DISEASE
HYPERTHYROIDISM HYPOTHYROIDISM
POLYGLANDULAR DEFICIENCY SYNDROME THYROID CANCER
THYROIDITIS THYROID NODULE
THYROID STORM
For further discussion of the thyroid gland
within the context of the endocrine system’s
structure and function please see the overview
section “The Endocrine System.”
See also AGING, ENDOCRINE CHANGES THAT OCCUR
WITH; HYPERCALCEMIA; HYPERPARATHYROIDISM; HYPO-
CALCEMIA; HYPOPARATHYROIDISM.
thyroiditis INFLAMMATIONof the follicular cells of
the THYROID GLAND. The inflammation prevents
these cells from synthesizing thyroid hormones,
resulting in HYPOTHYROIDISM. In some forms of thy-
roiditis the inflammation resolves and the follicu-
lar tissue returns to normal thyroid HORMONE
production. In other forms the inflammation heals
but forms SCAR tissue (fibrosis), permanently
destroying the ability of the affected follicular cells
to synthesize thyroid hormones. Thyroiditis does
not affect the parafollicular cells in the thyroid
gland that produce CALCITONIN.
The three main types of thyroiditis are
- autoimmune thyroiditis, sometimes called
Hashimoto’s thyroiditis or chronic lymphocytic
thyroiditis, which often develops in people who
have other AUTOIMMUNE DISORDERSand is the
most common type of thyroiditis - silent thyroiditis, which often develops in
women who have recently given birth and gen-
erally begins with HYPERTHYROIDISM - subacute thyroiditis, also called granulomatous
thyroiditis or subacute lymphocytic thyroiditis,
which typically develops after a viral INFECTION
Other rare types of thyroiditis include Reidel’s
thyroiditis, in which the thyroid becomes fibrotic
thyroiditis 163
THYROIDITIS SYMPTOMS AND TREATMENT
Autoimmune (Hashimoto’s) Silent Thyroiditis Subacute Thyroiditis
Thyroiditis
no PAIN no pain pain
gradual hypothyroid onset: hyperthyroid onset within four rapid hyperthyroid onset: weight loss,
progressive fatigue, weight gain, months of CHILDBIRTH: weight anxiety, insomnia, agitation
mild GOITER loss, anxiety, insomnia, agitation transition to hypothyroid: weight gain,
permanent destruction of thyroid no treatment for HYPERTHYROIDISM fatigue, lethargy
follicular cells because duration is short swelling and tenderness of neck
permanent HYPOTHYROIDISMwith transition to hypothyroid eight NONSTEROIDAL ANTI-INFLAMMATORY DRUGS
lifelong thyroid supplement months after childbirth: weight (NSAIDS) may relieve pain and some
HORMONE THERAPY gain, fatigue, lethargy, DEPRESSION INFLAMMATION
damage to thyroid follicular cells THYROID GLANDoften fully recovers and
often permanent, with resulting no treatment is necessary
permanent hypothyroidism permanent hypothyroidism requires
lifelong thyroid supplement hormone lifelong thyroid supplement hormone
therapy therapy