The pituitary gland is a very small endocrine gland; it is no larger than a pea or a cherry stone.
The pituitary gland lies in a small pocket of bone that is found at the base of the skull, in the middle of the head, directly behind your nose.
Despite its small size, the pituitary gland plays a key role in the body’s hormonal or endocrine system by controlling the production and release of many different hormones throughout the body. These hormones are involved in your growth, sexual development and reproductive function, metabolism and response to stress.
The pituitary gland controls the function of the thyroid and adrenal glands, with effects on metabolism, energy levels and the balance of salt and water in the body.
Growth hormone, which is also known as somatotropin, is a hormone produced by the pituitary gland throughout your life.
Growth hormone is secreted in short bursts or pulses, particularly during sleep.
In children, the release of growth hormone from the pituitary is responsible for skeletal growth. In adults, it is involved in the metabolism of muscles, bone and fat tissue.
Most of the actions of growth hormone on the body are mediated by another important hormone called insulin-like growth factor 1 (IGF-1). The liver produces this hormone.
The overproduction of growth hormone is usually caused by the presence of a benign tumour (an adenoma) within the pituitary gland.
While having a tumour in the head sounds very worrying, benign means not cancerous. So acromegaly is not a type of cancer.
In adults, a long-standing excess of growth hormone causes growth of soft tissues, bone and cartilage, mainly at the hands, feet, forehead and jaw. It can also cause water retention.
Additionally, the internal organs can also grow in size, which may lead, for example, to an enlarged heart and eventually to heart disease if not recognised and treated.
Other possible consequences of too much growth hormone are diabetes mellitus, joint problems, sleep problems (sleep apnoea syndrome) and carpal tunnel syndrome.
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