What autoimmune condition is characterized by excess production of thyroxine?

Grave's disease is an autoimmune condition characterized by an overstimulation of the thyroid gland, leading to an excess production of thyroxine (T4). This condition occurs when the immune system mistakenly attacks the thyroid gland, causing it to produce too much thyroid hormone. The symptoms of Grave's disease often include weight loss, rapid heartbeat, increased appetite, and anxiety, among others. This hyperthyroidism arises due to the production of antibodies that activate the thyroid-stimulating hormone (TSH) receptor, mimicking the action of TSH and stimulating excessive thyroid hormone production.

In contrast, Hashimoto's thyroiditis is another autoimmune condition but typically leads to hypothyroidism, where the thyroid gland is underactive and produces insufficient hormone levels. Addison's disease and Cushing's syndrome also involve hormone production but affect different glands and hormones entirely; Addison's disease involves insufficient production of adrenal hormones, and Cushing’s syndrome results from excess cortisol production. Thus, the specificity of Grave's disease in relation to thyroxine makes it the correct choice for identifying the autoimmune condition characterized by excess production of this hormone.