Hyperthyroidism is a term simply meaning an overactive thyroid gland. The metabolism of a person with hyperthyroidism is sped up from too much thyroid hormone in their system, so that everything in the body is running at overdrive. When this happens, the person will experience hyperthyroid symptoms, which include; rapid heart rate, hyperventilation, hypertension, sweating, inability to sleep, nervousness and anxiety, diarrhea, excessive energy followed by fatigue, hair loss, weight loss and swelling of the thyroid gland (goiter).

The vast majority of people with hyperthyroidism (95%) have Grave’s Disease as the cause. This is an autoimmune disease caused by antibodies created by the immune system that attach to the thyroid gland and stimulate it to produce excessive amounts of hormone. The main antibodies responsible for causing Grave’s Disease are called “Thyroid Stimulating Immunoglobulins” (TSI). When a person has hyperthyroidism, these antibodies are blood tested for to determine whether the cause is from this common autoimmune thyroid disease.

Most people with Grave’s Disease have “toxic diffuse goiters”, meaning they have an enlarged thyroid that is over-producing. These type goiters are also commonly painful in newly diagnosed Grave’s patients. This disease can also have complications and co-morbid conditions with it, including one called “Thyroid Eye Disease” (TED) an inflammatory condition that can cause swelling and bulging of the eyes and possible loss of vision, if not treated early.

Another cause of hyperthyroidism, are tumors called “thyroid nodules” that can develop in a person’s thyroid gland, that begin to absorb iodine and produce thyroid hormones, as if they have become a part of the thyroid gland. These type nodules are called “hot nodules” and are a less common cause of hyperthyroidism but when they do cause thyroid hormone imbalance, it is sometimes referred to as “nodular thyroid disease”. Rarely, in some women, tumors on their ovaries can also cause hyperthyroidism as can tumors that occur rarely in the pituitary gland.

While Grave’s Disease is considered a type of autoimmune thyroiditis, there are non-autoimmune types of temporary thyroiditis that can also cause periods of hyperthyroidism, before they resolve over several weeks or months. The most common type of temporary thyroiditis that causes hyperthyroidism is “sub-acute thyroiditis”.

Lastly, there are medications containing high levels of iodine that can result in the patient taking them, to experience hyperthyroidism. The same is true of iodine found in over-the-counter supplements and in products containing high levels of iodized salt.

If you experience some or all of the symptoms listed in the first paragraph of this article, see your Doctor about being tested for hyperthyroidism. The most common blood test ordered to detect over-activity by the thyroid gland is the “TSH” (pituitary hormone that reflects thyroid hormone levels). Some Doctors will also order tests of the “T-4 and T-3” thyroid hormone levels if the TSH level is abnormally low (decreases with too much thyroid hormone). If thyroid hormones are found to be high, tests for Grave’s Disease (including TSI antibodies) would likely follow.