| Term |
Definition |
| Multiple Endocrine Neoplasia Type 1 | This is a rare inherited condition in which affected individuals tend to develop tumours of the pituitary gland. |
| Neurohypophysis | An alternative name for the posterior pituitary gland. |
| Non-functioning tumour | A tumour which does not produce any of the pituitary hormones. |
| Octreotide | A somatostatin analogue used to reduce levels of growth hormone. |
| Oestrogen | Female sex hormone, which is produced by the ovaries. |
| Oligomenorrhoea | Abnormally infrequent menstrual periods. Often the interval between periods exceeds 40 days. |
| Optic Nerve Hypoplasia | Rare congenital underdevelopment of the midline of the brain affecting sight, and sometimes producing hypopituitarism, diabetes insipidus, and possible failure of the adrenal and thyroid glands. |
| Osteoporosis | Thinning of the bones with increased risk of bone fracture. The condition is associated with deficiency of oestrogen or testosterone. Osteopenia is the term given to milder bone thinning, less severe than osteoporosis. |
| Parlodel | The brand name of bromocriptine. |
| Pituitary gland | A gland, as small as a pea, located at the base of the brain. It produces hormones, which in turn control the hormone production of many other glands in the body. |
| Pituitary tumour | A tumour, almost always non-cancerous, of the pituitary gland. |
| Progesterone | Female sex hormone, which is produced by the ovaries. |
| Prolactin | A hormone often called the 'milk hormone' because its main function is to stimulate the breasts after childbirth. However, men also have prolactin, although the function of this hormone in males is not clear. |
| Prolactinoma | A pituitary tumour which produces prolactin. This can be a microprolactinoma or macroprolactinoma. |
| Radiotherapy | Treatment with X-rays. |
| Recombinant human GH | Synthetically produced growth hormone, which has the same structure as natural human growth hormone. |
| Sandostatin | The brand name of octreotide. |
| Septo Optic Dysplasia | Rare congenital underdevelopment of the midline of the brain affecting sight, and sometimes producing hypopituitarism, diabetes insipidus, and possible failure of the adrenal and thyroid glands. |
| Sex hormones | Luteinising hormone (LH) and follicle-stimulating hormone (FSH) are produced by the pituitary gland and stimulate the ovaries to produce oestrogen (in women) and testosterone (in men). |
| Short stature | Often due to underproduction of growth hormone. |
| Sleep apnoea | A condition in which you stop breathing for a few moments while asleep. This causes poor quality sleep such that you wake in the morning with a headache and still feeling tired, and can result in you falling asleep during the day. The partners of sufferers typically complain they are bad snorers. Sleep apnoea is a common disorder in patients with acromegaly. |
| Somatostatin | A naturally occurring hormone that reduces GH release from the pituitary gland. Man-made modified versions of somatostatin are known as somatostatin analogues. |
| Somatotrophin | Growth hormone. |
| Somatuline LA | The brand name of lanreotide. |
| Subcutaneous injection | An injection under the skin, as opposed to deeper into the muscle. |