Goiter
What is goiter?
Goiter is an enlargement of the thyroid gland. The thyroid gland is a small
gland located in the neck, below your Adam’s apple. The thyroid can be
enlarged due to generalized enlargement of the thyroid or nodules (tissue
growths) within the thyroid. The thyroid gland produces the hormones thyroxine
(also called T4) and a small amount of triiodothyronine (also called T3). Most
of the T4 is converted to T3 outside of the thyroid. These thyroid hormones
influence such bodily functions as a person’s body temperature, mood and
excitability, pulse rate, digestive functions, and other processes necessary for
life. It is important to understand that goiter is not cancer and that most
goiters are, in fact, benign.
What causes goiter?
Goiters have different causes depending on their type. Goiters can be
classified as simple, hereditary, or due to other causes. Simple goiters are
further classified as endemic (colloid) or sporadic (nontoxic).
Simple goiters are caused by an inadequate supply of thyroid hormone to meet
the body’s need. The thyroid gland tries to make up for this deficiency by
enlarging.
Endemic goiters occur in people within certain geographic areas who do not
get enough iodine in their diet (iodine is necessary to make thyroid hormone).
The use of iodized table salt in the United States has limited the development
of this type of goiter; however, iodine deficiency is still common in parts of
central Asia and central Africa.
Sporadic goiters have no known cause. Sometimes certain types of drugs, such
as lithium or aminoglutethimide, can cause this type of goiter.
Hereditary factors also may cause goiters. Risk factors for goiter
development include:
- Female gender
- Age over 40
- Family history of goiter
Other diseases and conditions can also cause a goiter. These
include:
- Graves’ disease. Graves’ disease is an autoimmune
disease (a disease in which your body’s immune system mistakenly attacks
your healthy body). In this case, the thyroid gland is attacked, which causes
it to overstimulate and results in swelling of this gland.
- Hashimoto’s disease. This is another autoimmune disease.
In this case, the disease causes inflammation of the thyroid gland, which in
turn, results in underproduction of thyroid hormones. Attempts by other
hormones to stimulate the thyroid gland cause it to enlarge.
- Nodular goiter. In this condition, tissue growths occur on
one or both side of the thyroid gland, resulting in an enlargement.
- Thyroid cancer.
Cancer of the thyroid gland often enlarges
the thyroid. Thyroid cancer can be found in thyroid nodules though less
than 5 percent of nodules are cancerous. A goiter without nodules is not a
concern for cancer.
- Pregnancy. A hormone secreted during pregnancy (human
chorionic gonadotropin) can cause an enlargement of the thyroid gland.
- Thyroiditis.
Inflammation of the thyroid gland itself can
result in an enlargement of the thyroid gland. This can follow a viral illness
or pregnancy.
- Exposure to radiation.
What are the symptoms of goiter?
Main symptoms include:
- A swelling, ranging in size from a small nodule to a massive
lump, in the front of the neck just below your Adam’s apple.
- A feeling of tightness in the throat area.
- Difficulty breathing (shortness of breath), coughing, wheezing
(due to compression of the windpipe).
- Difficulty swallowing (due to compression of the esophagus).
- Hoarseness.
- Neck vein distention.
- Dizziness when the arms are raised above the head.
Other symptoms can include:
- An increased resting pulse rate.
- Rapid heartbeat.
- Diarrhea, nausea, vomiting.
- Sweating without exercise or increased room temperature.
- Shaking.
- Agitation.
(The above group of symptoms are signs of hyperthyroidism -- a condition in
which the thyroid is overstimulated. Some people with goiter may also have
hyperthyroidism.)
- Fatigue, constipation, dry skin
- Weight gain
- Menstrual irregularities
(The above group of symptoms are signs of hypothyroidism -- a condition in
which the thyroid is underactive. Some people with goiter may also have
hypothyroidism.)
How is goiter diagnosed?
Several testing methods can be used to diagnose goiter, including:
- Physical exam – Your doctor may be able to determine
enlargement of the thyroid gland by feeling your neck area for nodules and
signs of tenderness.
- Hormone test – A blood test to determine thyroid
hormone levels (these tell you if the thyroid is functioning properly)
- Antibody test – A blood test to look for the
production of certain antibodies that are produced in some forms of goiter.
- Ultrasound of the thyroid –An imaging test of your
thyroid gland that reveals the gland’s size and possible presence of
nodules.
- Thyroid scan – Another imaging test that provides
information on the size and function of the gland. This test involves the
use of a small amount of radioactive material injected into a vein.
- CT scan or MRI (magnetic resonance imaging) scan of the
thyroid. These imaging tests are used to evaluate the size and extent of
the goiter.
How is goiter treated?
Treatment options depend on the size of the enlargement, your symptoms, and
the underlying cause. Treatments typically considered by your doctor include:
No treatment/"watchful waiting." If the goiter is small and not
bothering you, your doctor may decide that no treatment is necessary at this
time, but will continue to watch your condition for changes.
Medications. Levothyroxine (Levothroid, Synthroid) is a thyroid hormone
replacement therapy that can be prescribed if your doctor determines that the
cause of your goiter is an underactive thyroid (a condition called
hypothyroidism). Other medications can be prescribed if tests indicate your
thyroid is overactive (hyperthyroidism). Aspirin or a corticosteroid mediation
might be prescribed if the underlying cause of your goiter is inflammation.
Small does of iodine (in the form of Lugol’s or potassium iodine solution) can
be prescribed if the goiter is due to iodine deficiency.
Radioactive iodine treatment. This treatment, used in cases of an
overactive thyroid gland, involves injecting radioactive iodine into your
bloodstream. The iodine is delivered to the thyroid gland, killing thyroid
cells, which shrinks the gland. Radioactive iodine treatment is usually followed
by the use of hormone replacement therapy for life.
Biopsy. This may be required if you have large nodules in the thyroid to
exclude cancer.
Surgery. Surgery, to remove all or part of the thyroid gland, may be
necessary if the goiter is large and causing difficulty with breathing and
swallowing or sometimes to remove nodules and certainly if cancer is present.
Depending on the amount of thyroid gland removed, lifelong thyroid hormone
replacement therapy may be necessary.
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Copyright 1995-2006 The Cleveland Clinic Foundation. All rights reserved
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