What is Acromegaly?

Acromegaly is a rare disorder caused by a noncancerous tumor on the pituitary gland, which is located just below the brain. The pituitary gland controls many body functions, including growth, metabolism and reproductive function.

In acromegaly, a tumor that grows on the pituitary gland produces too much GH, which can prompt the liver to overproduce IGF-1. Too much GH or IGF-1 in the bloodstream signals the body to grow, and can result in a wide range of signs and symptoms.

According to the National Organization for Rare Disorders (NORD), acromegaly occurs in about 60 people for every one million in the United States, classifying it as a rare disease. Because acromegaly is often misdiagnosed or overlooked, these numbers likely underestimate how many people may be living with the disease.  While the disorder is most often diagnosed in middle age, acromegaly does not appear to be gender-specific, as it affects men and women equally.


Acromegaly – a rare disorder caused by a noncancerous tumor on the pituitary gland

Pituitary tumor – also known as adenoma, a benign tumor on the pituitary gland

GH – growth hormone, regulates the physical growth of the body, stimulates the production of IGF-1

IGF-1 – insulin-like growth factor 1, produced by the liver, drives tissue growth in the body

Somatostatin analog – a medical therapy that inhibits the production and release of GH into the bloodstream and may reduce pituitary tumor size; currently available as an injection into muscle or deep into tissue underlying the skin

Growth hormone receptor antagonist – a medical therapy that interferes with the action of GH and normalizes IGF-1 levels in majority of patients, but does not lower GH levels

Dopamine agonist – a medical therapy that normalizes IGF-1 levels in a minority of patients and may be used in combination with somatostatin analogs

Wear-off effects – when the positive effects of somatostatin analog treatment start to fade toward the end of the treatment cycle, may lead to the onset of acromegaly-related symptoms

Breakthrough symptoms – the onset of acromegaly-related symptoms despite a treatment regimen with somatostatin analog and/or having GH and IGF-1 levels in a normal range

Gigantism – a rare pituitary disorder caused by a noncancerous tumor on the pituitary gland during childhood, before the growth plates fuse after puberty


National Endocrine and Metabolic Diseases Information Service (NEMDIS); A service of the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), National Institutes of Health (NIH). Acromegaly Fact Sheet. Retrieved April 1, 2016.
2 UCLA Health (2015). Acromegaly [Fact sheet]. Retrieved April 1, 2016.
3 National Organization for Rare Disorders. (2014). Acromegaly [Fact sheet]. Retrieved April 1, 2016.
4 Medscape (2015). Gigantism and Acromegaly [Fact sheet]. Retrieved April 1, 2016.
5 Shlomo B, et al. Clinical, quality of life, and economic value of acromegaly disease control. Pituitary (2011) 14:284–294. Retrieved April 1, 2016.
6 Burton T, et al. Real-world comorbidities and treatment patterns of patients with acromegaly in two large US health plan databases. Pituitary (2013) 16:354–362. Retrieved April 1, 2016.