Hyperthyroidism is a condition in which the thyroid gland produces too much of the thyroid hormone. Normally, the pituitary gland in the brain releases thyroid-stimulating hormone (TSH), which orders the thyroid gland to produce thyroxine. Thyroxine, when converted to triiodothyronine, increases cell metabolism. Because a normal thyroid gland controls and regulates metabolism, an overactive thyroid may result in sudden weight loss, rapid heart rate, or excessive sweating. In addition to these symptoms, more common symptoms include fatigue, depression, and trouble sleeping.   

A physical exam is used to check for an enlarged thyroid, also known as goiter. Levels of TSH and thyroxine are determined by a patient’s blood sample. Low or nonexistent levels of TSH and high levels of thyroxine indicate hyperthyroidism.
Hyperthyroidism can be treated with drugs that impede thyroid hormone production; however, long-term patient follow-up is encouraged to maintain thyroid hormone levels. Patients unable to tolerate antithyroid drugs are given the option of undergoing radioactive iodine therapy. This treatment works by destroying most or all of the tissue in the thyroid gland. Although proven successful in most cases, radioactive iodine therapy exposes the patient to radiation, which increases the risk for long-term side effects. During radioactive iodine therapy, patients are required to take necessary precautions such as avoiding people and maintaining utmost cleanliness to ensure the safety of others.    
Surgical removal of all or part of the thyroid gland is a third option for patients who cannot be successfully treated with antithyroid drugs or radioactive iodine. Both radioactive iodine therapy and surgery pose a high risk for the patient’s thyroid to become underactive, known as hypothyroidism.