The hypersecretion of growth hormone (GH) in children results in the condition known as gigantism, where the person becomes abnormally tall due to excessive growth. In adults, however, excessive secretion of growth hormone can lead to acromegaly, a condition characterized by enlarged extremities such as the hands, feet, and facial features.
Gigantism occurs during childhood when the growth plates are still open, allowing for continued height growth. In contrast, acromegaly occurs after the growth plates have closed, thus leading to the thickening of bones and tissues instead of increased height. Both conditions arise from tumors of the pituitary gland that produce excess growth hormone.