Pituitary gigantism: Excessive growth and too much height due to chronic overactivity of the pituitary gland which is located at the base of the brain. (Growth hormone is specifically made by the anterior pituitary gland.)
In pituitary gigantism, there is secretion of too much growth hormone before the end of adolescence. People with pituitary gigantism can truly be giants. They can sometimes end up over 7 or 8 feet in height.
When too much growth hormone is secreted after adolescence, there cannot be an increase in height but a condition called acromegaly ensues. The cardinal manifestations of acromegaly include thickening of the skin, soft tissues, and bones of the hands and feet. These effects are insidious and very slowly progressive. Ultimately they cause considerable disability (aside from the need for larger rings, gloves, and shoes) including hoarseness, sleep apnea, joint pain, cardiovascular disease, hypertension, insulin resistance, visual impairment and severe headaches.
Pituitary gigantism and acromegaly may be caused by an adenoma of the pituitary (a tumor of the pituitary) or by other causes. Treatment is usually possible via medication or surgery. Inadequate treatment of pituitary gigantism and acromegaly is associated with increases in deaths from cardiovascular causes, cancer, and other causes.