Merck Manual

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Last full review/revision Apr 2019| Content last modified Apr 2019
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The pituitary gland is a pea-sized bit of tissue at the bottom of your brain. Glands are organs that make and release hormones into your blood. Hormones are chemicals that stimulate other cells or tissues into action. The pituitary gland puts out many different hormones. Each one controls different other glands and body functions.

Locating the Pituitary Gland

Locating the Pituitary Gland

What is hypopituitarism?

"Hypo" means too little or not enough. Hypopituitarism is when your pituitary gland doesn't make enough of one or more pituitary hormones.

  • Hypopituitarism is uncommon

  • Causes of hypopituitarism include tumors in your pituitary gland, not enough blood supply to your pituitary gland, or certain diseases

  • Symptoms usually start slowly over time and vary depending on which hormones you don't have enough of

  • Doctors treat the cause of hypopituitarism and give you medicine to raise your hormone levels

What causes hypopituitarism?

Causes of hypopituitarism include:

  • A brain tumor in your pituitary gland

  • A head injury

  • Certain types of brain surgery

  • Lack of blood flow to the pituitary gland, because of bleeding or a blood clot

  • Some types of cancer medical treatment, or radiation to the brain for a brain tumor

Sometimes there's a problem with only one pituitary hormone. Other times, you have a problem with many or all of the hormones.

What are the symptoms of hypopituitarism?

Symptoms usually start little by little. Which symptoms you have depend on which hormones you lack.

Symptoms can include:

  • In children, lack of growth

  • In women, lack of menstrual periods and vaginal dryness

  • In men, shrinking testicles and erectile dysfunction

  • Confusion, weight gain, and constipation

  • Weakness, low blood sugar, and feeling stressed

  • Not being able to make breast milk after having a baby

How can doctors tell if I have hypopituitarism?

Doctors may suspect hypopituitarism when you have problems with other glands, such as the thyroid gland. They'll do tests, such as:

  • Blood tests to measure your hormone levels

  • CT scan or MRI of your brain to look for changes to your pituitary

  • Sometimes, tests to check blood flow to your pituitary

How do doctors treat hypopituitarism?

Doctors treat hypopituitarism with:

  • Treatment for whatever is causing your hypopituitarism (for example, surgery or radiation to remove or destroy a pituitary tumor)

  • Replacing the hormones your pituitary isn't making enough of

NOTE: This is the Consumer Version. DOCTORS: Click here for the Professional Version
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