The pituitary is a small gland inside the head, behind the bridge of the nose. The pituitary is sometimes called the master gland because it plays a critical role in regulating growth and development, metabolism, and reproduction. The eye nerves sit directly above the pituitary gland. Enlargement of the gland can cause local symptoms such as headaches or visual disturbances. Pituitary tumors may also impair production of one or more pituitary hormones, causing reduced pituitary function (hypopituitarism).
The major pituitary hormones and their effects are: prolactin - controls formation of breast milk, influences fertility, and influences bone strength; growth hormone - regulates body growth, especially during adolescence; adrenocorticotropin (ACTH) - stimulates the adrenal glands to produce cortisol; thyrotropin (TSH) - stimulates the thyroid gland to produce thyroid hormones; luteinizing hormone (LH) - stimulates the ovaries or testes to produce sex hormones that determine many features of "maleness" or "femaleness"; and follicle stimulating hormone (FSH) - regulates fertility in men through sperm production and in women through ovulation.