The main cause of an overactive gland is another autoimmune disorder, Graves' disease, named for the 19th-century Irish physician who was one of the first to describe it. Although some Graves' patients feel supercharged and wired, they may at the same time feel weak and wiped out. Many people affected by hyperthyroidism also develop eye problems, including redness, irritation, dryness or swelling. For a small percentage of patients, symptoms include increased pressure on the optic nerve or tissue buildup behind the eyes, causing bulging from the sockets. Treating an overactive thyroid can also be tricky.
Most doctors recommend radioactive iodine.
For about 90 percent of patients, this treatment also involves the use of thyroid hormones to bring levels back to normal. Since Graves' disease can go into remission, a doctor may decide to try other drugs instead. In about five percent of cases, however, the medications cause side effects, including a rash, low-grade fever or joint aches. Blood tests can diagnose thyroid disorders. A proper thyroid test measures both TSH and the principal thyroid hormone, thyroxine.