Patient Education - Endocrine Encyclopedia
Endocrine Surgery Encyclopedia
Definition:
A goiter is an enlargement of the thyroid gland. It is not cancer.
Causes, incidence, and risk factors:
There are different kinds of goiters. A simple goiter usually occurs when the thyroid
gland is not able to produce enough thyroid hormone to meet the body's needs. The
thyroid gland makes up for this lack by enlarging, which usually overcomes mild deficiencies
of thyroid hormone.
A simple goiter may be classified as either an endemic (colloid) goiter or a sporadic
(nontoxic) goiter.
Endemic goiters occur within groups of people living in geographical areas with
iodine-depleted soil, usually regions away from the sea coast. People in these communities
might not get enough iodine in their diet (iodine is vital to the formation of thyroid
hormone). The modern use of iodized table salt in the U.S. prevents this deficiency.
However, inadequate iodine is still common in central Asia and central Africa.
In most cases of sporadic goiter the cause is unknown. Occasionally, certain medications
such as lithium or aminoglutethimide can cause a nontoxic goiter.
Hereditary factors may cause goiters. Risk factors for the development of a goiter
include female sex, age over 40 years, inadequate dietary intake of iodine, residence
in an endemic area, and a family history of goiter.
Symptoms:
-
Thyroid enlargement varying from a single small nodule to massive enlargement (neck
lump)
- Breathing difficulties, cough, or wheezing due to compression of the windpipe
- Swallowing difficulties due to compression of the esophagus
- Neck vein distention and dizziness when the arms are raised above the head
Signs and tests:
- Measurement of thyroid stimulating hormone (TSH) and free thyroxine (T4) in the
blood
- Thyroid scan and uptake
- Ultrasound of thyroid -- if nodules are present, a biopsy should be done to
check for thyroid cancer
Treatment:
A goiter only needs to be treated if it is causing symptoms. The enlarged thyroid
can be treated with radioactive iodine to shrink the gland or with surgical removal
of part or all of the gland (thyroidectomy). Small doses of iodine (Lugol's or potassium
iodine solution) may help when the goiter is due to iodine deficiency.
Support Groups:
Expectations (prognosis):
A goiter is a benign (harmless) process. A simple goiter may disappear on its own,
or may become large. Over time, hypothyroidism (not enough thyroid hormone) may develop
due to destruction of the normal thyroid tissue. This can be treated with medications
to replace the thyroid hormone.
Occasionally, a goiter may progress to a toxic nodular goiter when a nodule is
making thyroid hormone on its own. This can cause hyperthyroidism (too much thyroid
hormone) and can be treated with radioactive iodine to destroy the nodule.
Complications:
- Progressive thyroid enlargement or the development of hardened nodules may mean
thyroid malignancy. All thyroid nodules should be biopsied to check for cancer.
- A simple goiter may progress to a toxic nodular goiter.
- Hypothyroidism may occur after treatment of a large goiter with radioactive
iodine or surgery.
Calling your health care provider:
Call your health care provider if you experience any swelling or enlargement in the
front of your neck, increased resting pulse rate, or rapid heartbeats. Also call
if you have diarrhea, nausea, vomiting, sweating without exercise or increased room
temperature, shaking, agitation, shortness of breath, or signs of hypothyroidism
such as fatigue, constipation, or dry skin.
Prevention:
The use of iodized table salt prevents endemic goiter.
Review Date: 8/1/2005
Reviewed By: Nikheel S. Kolatkar, MD, Clinical and Research Fellow, Division of Endocrinology,
Diabetes, and Hypertension, Brigham and Women's Hospital, Harvard Medical School,
Boston, MA. Review provided by VeriMed Healthcare Network.
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