What condition is characterized by excessive secretion of thyroid hormone?

The condition characterized by excessive secretion of thyroid hormone is hyperthyroidism. Hyperthyroidism occurs when the thyroid gland produces too much thyroid hormone, leading to an acceleration of the body's metabolism. This can cause a range of symptoms including weight loss, rapid heartbeat, increased appetite, sweating, and nervousness, among others.

In contrast, hypothyroidism is characterized by insufficient production of thyroid hormone, leading to a slowing down of metabolic processes and resulting in symptoms such as weight gain, fatigue, and depression. Goiter refers to an enlargement of the thyroid gland, which can occur in both hyperthyroidism and hypothyroidism, but it is not a condition defined by hormone secretion levels. Dwarfism generally relates to a medical condition characterized by short stature and is not related to thyroid hormone levels at all. Thus, hyperthyroidism is the precise term for the excessive secretion of thyroid hormone.