What is the pituitary gland?

Your pituitary (hypophysis) is a pea-sized endocrine gland at the base of your brain, behind the bridge of your nose and directly below your hypothalamus. It sits in an indent in the sphenoid bone called the sella turcica. The pituitary gland is one of eight interrelated major endocrine glands:

  • Pineal gland.
  • Pituitary gland.
  • Thyroid gland.
  • Thymus.
  • Adrenal gland.
  • Pancreas.
  • Ovary (women only).
  • Testis (men only).

The pituitary is often referred to as the “master gland” because it not only secretes its own hormones, it tells other glands to produce hormones.

Your pituitary gland is divided into two main sections: the front (anterior) lobe and the back (posterior) lobe. Connecting the hypothalamus and pituitary gland is a stalk of blood vessels and nerves. Through that stalk, the hypothalamus communicates with the anterior lobe via hormones and the posterior through nerve impulses.

The hypothalamus, which is above your pituitary gland, is the control center of some of your body’s basic operations. It sends messages to your body’s autonomic nervous system, which controls things like blood pressure, heart rate, respiration, body temperature, sleep-wake cycle and digestion. The hypothalamus also tells the pituitary gland to produce and release hormones.

What does the pituitary gland do?

Glands are organs that secrete hormones — the “chemical messengers” of the body — that travel through your bloodstream to different cells, telling them what to do. The major hormones produced by the pituitary gland are:

  • ACTH: Adrenocorticotrophic hormone. Stimulates the production of cortisol, a “stress hormone” that maintains blood pressure and blood sugar levels.
  • FSH: Follicle-stimulating hormone. Promotes sperm production and stimulates the ovaries to produce estrogen.
  • LH: Luteinizing hormone. Stimulates ovulation in women and testosterone production in men.
  • GH: Growth hormone. Helps maintain healthy muscles and bones and manage fat distribution.
  • PRL: Prolactin. Causes breast milk to be produced after childbirth. It also affects hormones that control the ovaries and testes, which can affect menstrual periods, sexual functions and fertility.
  • TSH: Thyroid-stimulating hormone. Stimulates the thyroid gland, which regulates metabolism, energy and the nervous system.
  • Oxytocin: Helps labor to progress, causes breast milk to flow, affects labor, breastfeeding, behavior and social interaction and the bonding between a mother and child.
  • ADH: Anti-diuretic hormone, or vasopressin. Regulates water balance and sodium levels.

Hormones are not released from the pituitary gland in a steady stream. They come in bursts, every one to three hours, and alternate between periods of activity and periods of inactivity.

What happens when the pituitary gland doesn’t work properly?

Your pituitary gland plays such an important role that a lot can go wrong if it overproduces hormones (hyperpituitarism) or under-produces hormones (hypopituitarism). Overproduction or underproduction can affect metabolism, growth, blood pressure, sex functions and more.

Pituitary disorders occur when your pituitary gland fails to function as it normally should, likely because of a tumor, which is an abnormal growth of cells. Expert endocrinologists determined that about one in five people will get a tumor in their pituitary gland (16% to 20% of the population). Thankfully, the tumors are usually noncancerous (benign). Cancers of the pituitary gland rarely happen. Sometimes a pituitary gland will even have a tumor for years that’s both benign and doesn’t cause any symptoms.

There are two types of tumors: functioning and nonfunctioning. A functioning tumor produces hormones itself and a nonfunctioning tumor does not. Nonfunctioning tumors are more common.

You should see an endocrinologist, a specialist in the pituitary gland, if you have a tumor. You may also need to see an ophthalmologist (eye doctor) and neurosurgeon (a surgeon who operates on the brain, the head and the nervous system).

What are the symptoms of a pituitary tumor?

Many symptoms may point towards a pituitary tumor. If the tumor is putting pressure on the gland, your symptoms could include:

  • Headaches.
  • Vision problems (including trouble with peripheral vision).

If the pituitary gland is not producing enough hormones, your symptoms could include:

  • Fatigue.
  • Dizziness.
  • Dry skin.
  • Irregular periods (women).
  • Sexual symptoms (men).

Additional symptoms include:

  • Mood changes.
  • Irritability.
  • Muscle weakness.
  • Depression.
  • Menstrual cycle changes.
  • Erectile dysfunction.
  • Infertility.
  • Inappropriate breast growth.
  • Inappropriate production of breast milk.

There are several conditions that involve the pituitary gland:

  • Hypopituitarism: Hypopituitarism is when the pituitary gland doesn’t make enough hormones.
  • Acromegaly (Gigantism): Gigantism is a very rare disorder caused when the pituitary gland produces too much growth hormone (GH).
  • Diabetes Insipidus: This is a disorder affected by vasopressin, the antidiuretic hormone (ADH). If you have this disorder, your kidneys can’t retain water, which results in increased urination and increased thirst.
  • Hypogonadism: Also known as testosterone deficiency, this condition is a failure of the testes to make testosterone and/or sperm.
  • Prolactinoma: This is a type of tumor that causes the pituitary gland to produce too much of the prolactin hormone.
  • Galactorrhea: Galactorrhea is when a man or a woman produces breast milk when they’re not breastfeeding.
  • Cushing’s syndrome: This rare condition can happen when your body makes too much ACTH, which causes another gland in the body, your adrenal glands, to make too much cortisol. This condition can affect almost any tissue in the body.
  • Adult GH deficiency syndrome: Problems resulting from this syndrome include changes in body composition due to changes in fat and muscle, bad cholesterol levels and loss of energy and/or interest in hobbies and social activities.
  • Empty sella syndrome: The sella turcica is the bone structure that surrounds and protects the pituitary gland. Empty sella syndrome means that nothing appears, at first, to be inside that bone structure. The pituitary gland may be flat, smaller than normal, or regressed within the cavity because of an injury.
  • Sheehan’s syndrome (postpartum hypopituitarism): Sheehan’s syndrome occurs when a woman has severe uterine hemorrhage during childbirth. Such severe blood loss causes some of the pituitary gland tissues to die.
  • Craniopharyngioma: A craniopharyngioma is a rare tumor that puts pressure on the hypothalamus.
  • Multiple endocrine neoplasia (MEN): MEN causes multiple glands to develop tumors.
  • Lymphocytic hypophysitis: This is caused by immune cells that inflame the pituitary gland.

How are pituitary tumors treated?

Radiotherapy, medications and surgery may be necessary to treat a pituitary tumor.

  • Radiotherapy — which may be performed before or instead of surgery — uses highly focused x-rays (Gamma knife or X-knife Linac), usually over several weeks.
  • Medications are used to either reduce the levels of a particular hormone or replace a hormone that is under-produced.
  • Surgery is called transsphenoidal surgery where the neurosurgeon makes an incision inside your nostril or under your upper lip. You’ll stay in the hospital for about five days after the tumor is removed. Recovery times vary. It could be as short as four weeks to as long as eight weeks. Regular follow-ups will be required.

Pituitary tumors can regrow.

Your pituitary gland affects vital areas of your body. If your pituitary gland doesn’t function properly, your skin, brain, reproductive organs, vision, mood, energy, growth and more could all be negatively affected. Your body depends on the hormones it produces and releases.

Contact your healthcare provider to address any symptoms that might point towards your pituitary gland.

Last reviewed by a Cleveland Clinic medical professional on 10/08/2020.


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