Graves disease is characterized by

• A. Underproduction of thyroid hormone.
• B. Overproduction of cortisol.
• C. Overproduction of thyroid hormone.
• D. Infection of the thyroid.

Answer: (C)

Graves disease is an autoimmune form of hyperthyroidism where antibodies stimulate the thyroid’s TSH receptors, causing the gland to crank out more thyroid hormones (T3 and T4) than the body needs. This results in a hypermetabolic state with symptoms such as weight loss, heat intolerance, rapid heart rate, tremors, and often a goiter; exophthalmos can occur due to orbital tissue involvement. The pituitary may reduce TSH in response to the high thyroid hormone levels, but the autoimmune stimulation keeps thyroid hormone production elevated. The other possibilities don’t fit Graves: underproduction of thyroid hormone would be hypothyroidism; overproduction of cortisol points to a cortisol-related disorder like Cushing’s; infection of the thyroid describes thyroiditis, not Graves.