To help shrink a goiter naturally, reducing your intake of goitrogens may prevent further thyroid disruption, Dr. Quijano-Vega says. This doesn't mean you should swear off these foods entirely ...

In the United States, the most common cause of goiter is Hashimoto’s thyroiditis, says Dr. Barlow. This is an autoimmune disorder that causes hypothyroidism, or an underactive thyroid.