The thyroid gland is located at the base of the neck, in front of the trachea (windpipe) and esophagus (tube
that connects the mouth with the stomach). The thyroid produces thyroid hormone,
which helps to regulate many body functions. In hyperthyroidism, the thyroid is overactive and produces more thyroid hormone than
the body needs. Women are more likely than men to have hyperthyroidism, and
it affects younger persons more than elderly persons. The July 6, 2005, issue
of JAMA includes an article about hyperthyroidism
and the long-term effects of radioactive iodine treatment for hyperthyroidism.