How does iodine affect hyperthyroidism?

Hyperthyroidism can result from ingestion of too much iodine. One can ingest too much iodine from food or medications. In the United States, salt is iodized as an efficient way to add iodine to the diet. However, seafood and kelp also contain iodine. Changing medications or reducing certain items in the diet can treat hyperthyroidism when too much iodine is the cause.