Hypothyroidism | What Is An Underactive Thyroid?

July 12th, 2010 by admin

An underactive thyroid (hypothyroidism) occurs when the thyroid gland stops producing enough of the thyroid hormones, triiodothyronine (T3) and Thyroxine (T4). The disease mainly affects middle-aged and elderly women but it can also run in family groups. The thyroid gland shrinks as its cells are destroyed by the defect in the patient’s immune system.