What Does the Pituitary Gland Do?

Medically Reviewed By William C. Lloyd III, MD, FACS
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profile of male head with brain stem anatomy labeled, including thalamus, pituitary gland, pons, and medulla oblongata

The pituitary gland, also called the hypophysis, is a bit of a mystery for most people. It is a tiny, pea-sized gland that is part of your endocrine system. A gland is a small organ made up of cells with a very specific function. There are several glands in the endocrine system. They are responsible for making and secreting the hormones that circulate throughout your body.

Pituitary gland function is essential for survival and normal growth and development. Here are the facts on what the pituitary gland does and how it works as part of the endocrine system.

Pituitary Gland Function

Your pituitary gland is situated behind your nose at the base of the brain. At only about 1/3 of an inch in diameter, the pituitary gland is tiny, but it is a major part of the endocrine system. It is often called the ‘master gland’ because it controls how other endocrine glands work.

The gland has two distinct parts, the anterior and the posterior lobes. The anterior, or front, lobe is responsible for producing the sex and reproductive hormones, as well as those for the adrenal glands and thyroid, among others. They include:

  • ACTH: adrenocorticotropic hormone, which stimulates the release of cortisol (another hormone) from the adrenal glands
  • ADH: antidiuretic hormone, or vasopressin, which instructs your kidneys how much water to keep in your body
  • FSH: follicle-stimulating hormone, which is responsible for ovary follicle growth (which produce the hormones estrogen and progesterone) and gonad development and sperm development in men
  • GH: growth hormone, which helps children grow and adults maintain muscle and bone growth in adults, among other roles
  • LH: luteinizing hormone, which plays a role in ovary and testicular function
  • PRL: prolactin, which is released when a woman nurses a baby, but it also plays a role in maintaining the immune system and the reproductive system
  • TSH: thyroid-stimulating hormone, which controls your thyroid function

The posterior, or back lobe stores some hormones before they are released into the bloodstream.

Pituitary Gland and Hypothalamus Connection

The hypothalamus is at the base of the brain, connected to the pituitary gland. It releases hormones and regulates your body’s temperature, feelings of hunger, sleep, and other body functions. The hypothalamus directs the pituitary gland by telling it when it can release or not release hormones.

The pituitary gland’s anterior lobe is connected to the bottom of the hypothalamus by a tiny, slender stalk called the infundibulum.

Problems Associated with the Pituitary Gland

The pituitary gland can malfunction, which can have a serious impact on your health. Thankfully, pituitary gland disorders are not common.

In most cases, pituitary gland malfunction is triggered by a noncancerous (benign) tumor. Pituitary tumors are masses of cells. Tumors can press on the pituitary gland tissue causing excessive hormone secretion or a hormone deficiency. Some tumors occur in specific pituitary gland cells leading to increased production of a hormone.

Pituitary problems include:

  • Cushing’s syndrome: This rare condition is when you have too much human cortisol in your body.
  • Acromegaly: Another rare condition, acromegaly is caused by too much growth hormone.
  • Pituitary tumor: A pituitary tumor can also affect non-pituitary tissue at the base of the brain, such as the optic nerve resulting in vision changes.
  • Adrenal insufficiency: Low ACTH will cause symptoms of reduced cortisol and can cause diabetes.
  • Diabetes insipidus: Low ADH levels can cause diabetes insipidus, which can be treated with drugs that act like vasopressin.
  • Hypopituitarism: Low secretion of one or more hormones from the pituitary has many possible causes, from tumors to head injury to infection. Hypopituitarism symptoms depend on which hormone(s) are deficient.

Pituitary symptoms from a malfunctioning pituitary gland vary greatly. It depends on the affected hormone(s). In many cases, they come on gradually, such as delayed puberty for LH and FSH deficiency. Sudden changes in pituitary gland function or surrounding tissue can be medical emergencies. Signs to watch for include dehydration, change in level of consciousness or behavior, and loss of vision.

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Medical Reviewer: William C. Lloyd III, MD, FACS
Last Review Date: 2020 May 18
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