Your thyroid is a butterfly-shaped gland located at the base of your neck just below your Adam's apple. Sometimes the thyroid gland grows larger than normal — a condition known as goiter. Although goiters are usually painless, a large goiter can cause a cough and make it difficult for you to swallow or breathe.

The most common cause of goiter worldwide is a lack of iodine in the diet. In the United States, where most people use iodized salt, goiter is more often due to the over- or underproduction of thyroid hormones or to nodules that develop in the gland itself.

Treatment depends on the size of the goiter, your symptoms and the underlying cause. Small goiters that aren't noticeable and don't cause problems usually don't need treatment.