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A goiter is a non-cancerous enlargement of the thyroid gland. Simple goiters can develop when the body is lacking in sufficient thyroid hormone.
Sometimes a simple goiter may appear for no apparent reason. Endemic goiters and sporadic goiters are simple goiters.
Endemic goiters are also known as colloid goiters. They affect people who live in areas where soils are low in iodine, generally inland and away from the sea.
Diets then may be lacking in iodine, which is necessary for thyroid hormone production. Iodine deficiency is the usual cause for goiters.
According to a May 10, 2010 MedlinePlus article, at one time some areas of the United States were the "goiter belt," but now iodized table salt is in common use and iodine deficiency is rare.
Sporadic, or nontoxic, goiters generally spring from unknown causes. In other cases, a sporadic goiter can be the result of taking medications like aminoglutethimide or lithium.
It's possible that genetics may play a role in development of goiters. If you have a family history of goiter, if you are a female over the age of 40, or if you don't get enough dietary iodine, you may be a candidate for a goiter.
If your goiter is big enough you may notice a swelling in your throat ranging from the size of a small nodule to a lump that presses on your windpipe and esophagus.
Goiters can cause hoarseness and coughing and may make swallowing difficult. Occasionally a very big goiter could cause trouble breathing but this is rare.
A goiter can occur whether your thyroid is producing too little thyroid hormone (hypothyroidism), too much (hyperthyroidism), or even the right amount.
When too little thyroid hormone is produced, your pituitary gland sends thyroid stimulating hormone (TSH) to the thyroid to stimulate production of more hormone and to tell the thyroid to grow. This is where a goiter begins.
Graves' disease can cause goiter. Your immune system produces a protein called thyroid stimulating immunoglobulin (TSI) which causes the thyroid to become enlarged, leading to goiter.
But too much hormone can be produced. The pituitary will stop secreting TSH under these circumstances.