Hyperthyroidism is a condition in which the thyroid gland produces too much thyroid hormone. Every year, some 350,000 people develop some kind of hyperthyroidism, and it is eight to ten times more common in women than men.
If you develop hyperthyroidism, you may experience rapid and/or irregular heartbeat, tremors, weakness, heat intolerance, weight loss, mood swings, and more frequent bowel movements. Women may have lighter, less frequent menstruation. A related problem in 5% of patients involves the eyes, which can appear enlarged and bulging.
The most common cause (in the US, 70 to 80%) is Graves' disease, also called diffuse toxic goiter. This is an autoimmune disease in which your immune system overstimulates your whole gland to make too much hormone. About 5% of patients with Graves' disease also have some involvement with their eyes in which the eyes may become inflamed and appear enlarged. This is described as thyroid eye disease or "exophthalmos" in the articles about Graves' disease.
Ten percent of hyperthyroid patients have one or more small benign tumors in their gland, so-called "hot nodules," which make hormone at too high a rate. This is called toxic nodular goiter.
The diagnosis of hyperthyroidism of any type includes a test for thyroid stimulating hormone (TSH) from the pituitary gland, which will be low, its manufacture and release turned off by high thyroid hormone levels. Thyroid hormone levels of thyroxine (T4) and triiodothyronine (T3)are increased and indicate the degree of hypothyroidism. A radioactive scan or ultrasound may be needed to determine whether overactive thyroid nodules are the cause of the hyperthyroidism.
Treatment (in the short term) may focus on making the body less responsive to the stimulus given by the thyroid hormone, using beta adrenergic blocking agents like atenolol or propranolol. These help slow the pulse and calm your tremors and nerves. Other treatments may shut off iodine from the gland with antithyroid agents such as methimazole (Tapazole) or propylthiouracil (PTU), so it then makes less hormone.
Long-term treatment can reduce the number of hormone-making cells in the gland by using radioactive iodine, or alternatively a surgeon can remove part or all of the gland or the overactive "hot" nodules. If you are then producing too little hormone, it is easy to restore you to normal with a daily dose of thyroid hormone in pill form.
Less common causes include:
Did you know that some people with Graves' or Hashimoto's disease also have a tendancy to certain kinds of tendon and joint inflammation?