What condition is characterized by excessive production of growth hormone?

The condition characterized by excessive production of growth hormone is acromegaly. This occurs primarily due to a benign tumor of the pituitary gland, known as an adenoma, which leads to an overproduction of growth hormone. This excess growth hormone results in a variety of symptoms, including enlarged hands and feet, facial changes (such as a protruding jaw and enlarged nose), and various systemic effects that can impact overall health.

In contrast, dwarfism is associated with insufficient growth hormone, leading to short stature. Cushing's syndrome is caused by an excess of cortisol rather than growth hormone, and hyperthyroidism is characterized by an overproduction of thyroid hormones, which affects metabolism but not growth hormone levels. Therefore, the clear association of acromegaly with excessive growth hormone production makes it the correct answer.