A nontoxic goiter is a thyroid that has grown large enough to see as a mass in the neck. However, it is not malignant, and it does not overproduce the thyroid hormone, according to Dr. James Norman for EndocrineWeb. Thyroid enlargement occurs when the pituitary gland increases thyroid-stimulating hormone production.
A common cause of goiters in the United States is an increase in the thyroid-stimulating hormone known as TSH, Norman states. An iodine-deficient diet can cause a goiter, but it is rarely the cause because iodine is readily available in U.S. diets.
When the pituitary gland produces excess TSH in response to a defect in the normal hormone synthesis within the thyroid gland, the thyroid grows larger, Norman states. Years may pass before an enlarged thyroid becomes visible.
A large non-toxic goiter can compress the trachea and esophagus, causing symptoms such as coughing, a feeling that food is stuck in the upper throat or waking from sleep with a feeling of impaired breathing, Norman states. When thyroid glands grow large enough to compress the esophagus and trachea, surgical removal of the glands is the only way to relieve the symptoms.
Thyroid hormone pills are one treatment for small or moderate-sized goiters. The hormone pills reduce TSH production and stabilize goiter growth, but they do not shrink the goiter, Norman states.