What causes acromegaly?

Acromegaly is the result of too much growth hormone in the body. In most cases, a benign tumor on the pituitary gland causes the body to produce extra growth hormone. However, sometimes, tumors in other parts of the body can secrete hormones that trigger an excessive release of growth hormone, too. Since growth hormone is responsible for organ, bone, and muscle development, overproduction leads to an abnormal growth of these tissues. In children, this causes gigantism because the bones are still capable of increasing in length, while this is no longer true in adults. In adults, acromegaly causes a deformity of the bones and an enlargement of tissue, such as the heart.