The goiter typically shrinks 2 to 6 months after treatment, although it may take up to a year. Studies also have shown that in most cases, normal thyroid function continues or returns to normal after treatment. Smaller goiters respond better to radioiodine therapy than large ones.

Can thyroid nodules shrink on their own?

Thyroid nodules don't always need treatment. Most go away on their own. In some cases, the doctor may shrink a thyroid cyst by removing fluid from it with a needle, recommend surgery to remove the nodule, or prescribe medicine.

What causes thyroid nodules to shrink?

Radioactive iodine.

Doctors use radioactive iodine to treat hyperthyroidism. Taken as a capsule or in liquid form, radioactive iodine is absorbed by your thyroid gland. This causes the nodules to shrink and signs and symptoms of hyperthyroidism to subside, usually within two to three months.