Acromegaly is caused in adults when the body makes too much of the hormone that controls growth.
Hormones are produced by various parts of the body. They control many different functions in the body, affect almost every system in the body and also affect the emotions.
It is the pituitary gland, located in the brain, that produces growth hormone (as well as other hormones). If it produces too much growth hormone after you reach adulthood, you may suffer from acromegaly. Too much growth hormone in childhood may
result in gigantism, with the leg bones growing much longer than usual and the child growing much taller than expected.
People with acromegaly find their bones get bigger, including those in the face, hands and feet.
The growth hormone from the pituitary instructs the liver to produce another hormone. This is the so-called, insulin-like growth factor-I (IGF-I). It is this IGF-I that stimulates the growth of bones and other tissues.
There may be a hereditary effect with acromegaly and gigantism, with a group of people in Ireland carrying a gene, AIP-Related Acromegaly and Gigantism, that makes it more likely that one in five of those who carry it may suffer from gigantism (in children) or acromegaly (in adults). In one particular area, one in 150 people carry this gene, compared with 1 in 2000 elsewhere. This may have an effect in the United States with many people claiming descent from Irish immigrants.