What condition is characterized by an excess of thyroid hormones?

Hyperthyroidism is characterized by an excess production of thyroid hormones, primarily thyroxine (T4) and triiodothyronine (T3). This condition results in an acceleration of the body's metabolism, which can lead to a range of symptoms including increased heart rate, unintentional weight loss, anxiety, tremors, and heat intolerance. The most common cause of hyperthyroidism is Graves' disease, an autoimmune disorder that stimulates the thyroid gland to overproduce hormones.

In contrast, hypothyroidism indicates a deficiency of thyroid hormones, where metabolism slows down, leading to symptoms such as fatigue, weight gain, and sensitivity to cold. Diabetes mellitus is not directly related to thyroid function, as it primarily involves issues with insulin production and glucose metabolism. Cushing's syndrome is characterized by excess cortisol production and is unrelated to thyroid hormone levels. Understanding these distinctions is crucial for proper diagnosis and management of endocrine disorders.