The term nontoxic goiter refers to enlargement of the thyroid which is not associated with overproduction of thyroid hormone or malignancy. The thyroid can become very large so that it can easily be seen as a mass in the neck. There are a number of factors which may cause the thyroid to become enlarged. A diet deficient in iodine can cause a goiter but this is rarely the cause because of the readily available iodine in our diets. A more common cause of goiter in America is an increase in thyroid stimulating hormone (TSH) in response to a defect in normal hormone synthesis within the thyroid gland. Goiter is the medical term for enlargement of the thyroid gland. A butterfly shaped structure located in the front, lower section of the neck, the thyroid controls the speed at which the body’s metabolism operates. In children, the thyroid is essential for normal growth and development.
Goiter is often merely a symptom of a more serious thyroid condition, such as:
Hyperthyroidism , an overactive thyroid gland;
Hypothyroidism , an underactive thyroid gland;
Thyrotoxicosis , an excessive amount of thyroid hormone in the bloodstream;
Graves’ disease (also known as toxic diffuse goiter or exophthalmic goiter ), a form of hyperthyroidism.
If a child is born with an enlarged thyroid gland, it is referred to as congenital goiter. In some cases, a child may have Pendred’s Syndrome, a condition in which congenital goiter and deaf-mutism are both present. Goiter in a newborn can press on the windpipe, making breathing difficult.
Causes
There are various types and causes of goiter. In underdeveloped parts of the world, it is often brought on by a lack of iodine in the diet. Iodine—found in fish products, drinking water and table salt—is essential for the production of thyroid hormone. Without it, the gland enlarges in an attempt to increase the output of the hormone. The World Health Organization estimates that 750 million people still suffer from this problem, earning it the name endemic goiter.
The overactivity of the thyroid found in Graves’ disease is believed to be caused by an antibody that stimulates the thyroid to produce too much of the hormone. Goiter caused by Graves’ disease is accompanied by other problems such as bulging eyes, a rapid heartbeat, sweating, and anxiety.
In another form of goiter, called toxic nodular goiter, one or more nodules in the thyroid get out of control and produce too much thyroid hormone. In this case, the nodules are benign thyroid tumors and are not associated with other disorders.
Sporadic goiter is caused by an overgrowth of the thyroid gland. In certain other types of goiter, the cause is unknown.
Signs/Symptoms
The hallmark of goiter is swelling in or disfigurement of the neck. The swollen area is usually painless, but can be bothersome and psychologically disturbing due to its appearance.
The thyroid stimulating hormone comes from the pituitary and causes the thyroid to enlarge.
