Hyperthyroidism or overactive thyroid is a condition in which the thyroid gland produces too much thyroid hormone.

There are five main causes of hyperthyroidism:

-         Thyroiditis (swelling of the thyroid).

-         Autoimmune disorders.

-         Excessive iodine consumption.

-         Side-effect to certain drugs.

-         Lumps located in the thyroid gland

After completing a history and physical exam, thyroiditis can be diagnosed with blood tests, including complete blood count, thyroid stimulating hormone (TSH), and free thyroxine (T4).