Uncommon causes of
hyperthyroidism or too much thyroid hormone in the
body include:
- Taking too much thyroid hormone medicine. This
can happen if you are taking thyroid hormone to treat thyroid cancer. It can
also happen if you take too much thyroid hormone in an attempt to lose
weight.
- Taking large amounts of substances or medications that
contain iodine, such as iodized salt, kelp, cough syrups, multivitamins, or
certain medications, such as amiodarone, lithium, and interferon
alfa.
- Having too much thyroid hormone after
pregnancy.
- A growth in the uterus that releases hormones into a
woman's body, causing the thyroid to produce too much thyroid
hormone.
- A rare tumor that grows on a woman's
ovaries. The tumor contains thyroid tissue, which
releases thyroid hormone into the body.
- A rare tumor on the
pituitary gland located in your brain. This tumor
causes the pituitary gland to make too much thyroid-stimulating hormone (TSH).
TSH stimulates the thyroid gland to make more thyroid hormones.
- Stress, surgery, or using contrast materials containing iodine for
a
CT scan or radioactive iodine therapy.
The thyroid gland usually returns to normal after treatment. For
example, once you quit taking substances that contain large amounts of iodine
or a hormone-producing tumor is removed, the thyroid gland again works
normally.
