a doctor examining a patient for hyperthyroidism

Hyperthyroidism Causes

If you suffer from unexplained nervousness, irritability, increased perspiration, tremors and anxiety, you could be suffering from hyperthyroidism. Hyperthyroidism is a condition in which the body produces too much thyroid hormone, which is necessary for your metabolism to function properly. When there is too much thyroid hormone, your metabolism becomes overactive and causes the symptoms listed above. Hyperthyroidism can come on slowly or suddenly and is often mistaken for a nervous disorder.


There are several causes of hyperthyroidism. The most common, Graves’ disease, is a disorder in which the body’s antibodies attack the thyroid gland, in turn causing it to grow larger and secrete more thyroid hormone. Approximately 70% of people who have hyperthyroidism have Graves’ disease; research shows that it appears to be hereditary and manifests mainly in young women. Women who have Graves’ disease may appear to have bulging eyes and a telltale goiter, or swollen neck.

In addition to Graves’ disease, another condition that causes hyperthyroidism is the growth of nodules, or lumps, on the thyroid gland that cause an increase in the amount of thyroid hormone released into the blood. The hormones are released both by the nodules and the gland itself. This condition is called multinodular goiter or toxic nodular goiter. Finally, a condition called thyroiditis, caused by an infection or immune system anomaly, can result in extra thyroid hormone getting into the blood system and causing the symptoms of hyperthyroidism.


The good news about hyperthyroidism is that is very curable using several different treatments. Antithyroid drugs, such as Tapazole, stop the thyroid gland from making its hormones. Some of the drugs used for this purpose carry a number of unpleasant side effects, with Tapazole causing the fewest. However, a risk associated with all these drugs is a possible reduction in the body’s white blood cell count, which can lead to potentially deadly infections.

Another treatment doctors use is radioactive iodine. The iodine destroys the nodules and part or all of the thyroid gland, after which the thyroid hormone is taken orally to regulate metabolism. You might wonder about the toxic effects of being treated with iodine, but it has been used as a safe and effective treatment for more than 60 years. Surgery is yet another treatment option. Surgeons remove part or all of the thyroid gland and prescribe thyroid hormones to be taken orally.

Last Updated: March 09, 2016