What condition results from excessive growth hormone in adults?

The condition caused by excessive growth hormone in adults is acromegaly. It develops after the growth plates have closed, so the excess hormone enlarges bones and soft tissues rather than increasing a person’s height.

Most cases are caused by a benign growth-hormone-secreting adenoma of the pituitary gland. Excess growth hormone raises levels of insulin-like growth factor 1, or IGF-1, which drives gradual changes such as enlarged hands and feet, a more prominent jaw, thicker facial features, coarser skin, and a deeper voice.

Acromegaly often develops slowly, so people may not notice the changes for years. Rings, shoes, or gloves may stop fitting; headaches, joint pain, excessive sweating, sleep apnea, diabetes, and vision problems can also occur. A large pituitary tumor may press on nearby structures, including the optic pathways.

The key distinction is age at onset. Excess growth hormone before the growth plates close causes gigantism, characterized chiefly by excessive height. In adults, the same hormonal excess produces acromegaly. Doctors evaluate IGF-1 and growth hormone levels and may use magnetic-resonance imaging to look for a pituitary tumor.