Diet
People with autoimmune hyperthyroidism (such as in Graves disease) should not eat foods high in iodine, such as edible seaweed and kelps.From a public health perspective, the general introduction of iodized salt in the United States in 1924 resulted in lower disease, goiters, as well as improving the lives of children whose mothers would not have eaten enough iodine during pregnancy which would have lowered the IQs of their children. Surgery
Surgery (thyroidectomy to remove the whole thyroid or a part of it) is not extensively used because most common forms of hyperthyroidism are quite effectively treated by the radioactive iodine method, and because there is a risk of also removing the parathyroid glands, and of cutting the recurrent laryngeal nerve, making swallowing difficult, and even simply generalized staphylococcal infection as with any major surgery. Some people with Graves may opt for surgical intervention. This includes those that cannot tolerate medicines for one reason or another, people that are allergic to iodine, or people that refuse radioiodine.If people have toxic nodules treatments typically include either removal or injection of the nodule with alcohol. Radioiodine
In iodine-131 (radioiodine) radioisotope therapy, which was first pioneered by Dr. Saul Hertz, radioactive iodine-131 is given orally (either by pill or liquid) on a one-time basis, to severely restrict, or altogether destroy the function of a hyperactive thyroid gland. This isotope of radioactive iodine used for ablative treatment is more potent than diagnostic radioiodine (usually iodine-123 or a very low amount of iodine-131), which has a biological half-life from 8–13 hours.
Functional thyroid tissue producing an excess of thyroid hormone occurs in a number of clinical conditions. The major causes in humans are:

Graves disease. An autoimmune disease (usually, the most common cause with 50–80% worldwide, although this varies substantially with location- i.e., 47% in Switzerland (Horst et al., 1987) to 90% in the USA (Hamburger et al. 1981)). Thought to be due to varying levels of iodine in the diet. It is eight times more common in females than males and often occurs in young females, around 20 – 40 years of age. Toxic thyroid adenoma (the most common cause in Switzerland, 53%, thought to be atypical due to a low level of dietary iodine in this country)
Toxic multinodular goiterHigh blood levels of thyroid hormones (most accurately termed hyperthyroxinemia) can occur for a number of other reasons:

Inflammation of the thyroid is called thyroiditis. There are several different kinds of thyroiditis including Hashimotos thyroiditis (Hypothyroidism immune-mediated), and subacute thyroiditis (de Quervains). These may be initially associated with secretion of excess thyroid hormone but usually progress to gland dysfunction and, thus, to hormone deficiency and hypothyroidism. Oral consumption of excess thyroid hormone tablets is possible (surreptitious use of thyroid hormone), as is the rare event of eating ground beef or pork contaminated with thyroid tissue, and thus thyroid hormones (termed hamburger thyrotoxicosis or alimentary thyrotoxicosis). Pharmacy compounding errors may also be a cause. Amiodarone, an antiarrhythmic drug, is structurally similar to thyroxine and may cause either under-or overactivity of the thyroid.