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Hypopituitarism

Show Alternative Names
Pituitary insufficiency
Panhypopituitarism

Hypopituitarism is a condition in which the pituitary gland does not produce normal amounts of some or all of its hormones.

Causes

The pituitary gland is a small structure that is located just below the brain. It is attached by a stalk to the hypothalamus. The hypothalamus is the area of the brain that controls the pituitary gland's function.

The hormones released by the pituitary gland (and their functions) are:

  • Adrenocorticotropic hormone (ACTH) -- stimulates the adrenal gland to release cortisol; cortisol helps to maintain blood pressure and blood sugar
  • Antidiuretic hormone (ADH) -- controls water loss by the kidneys
  • Follicle-stimulating hormone (FSH) -- controls sexual function and fertility in males and females
  • Growth hormone (GH) -- stimulates growth of tissues and bone
  • Luteinizing hormone (LH) -- controls sexual function and fertility in males and females
  • Oxytocin -- stimulates the uterus to contract during labor and the breasts to release milk
  • Prolactin -- stimulates female breast development and milk production
  • Thyroid-stimulating hormone (TSH) -- stimulates the thyroid gland to release hormones that affect the body's metabolism

Pituitary gland - Animation

The pituitary gland is often referred to as the master gland of the body, since it regulates many activities of other endocrine glands. Located above the pituitary gland is the hypothalamus. The hypothalamus decides which hormones the pituitary should release by sending it either hormonal or electrical messages. In response to hormonal messages from the hypothalamus, the pituitary gland releases the following hormones. GH (growth hormone) - increases size of muscle and bone. THS (thyroid stimulating hormone) - stimulates the thyroid gland to release T3 and T4 to stimulate metabolism in other cells throughout the body. FSH (follicle stimulating hormone) - stimulates ovarian follicle production in women; stimulates sperm production in men. LH (luteinizing hormone) - stimulates ovaries to produce estrogen in women; stimulates sperm production in men. Prolactin - stimulates breast tissue in nursing mothers to produce milk. ACTH (adrenocorticotropic hormone) - causes the adrenal glands to produce important substances that have properties similar to steroids. In response to electrical messages from the hypothalamus, the pituitary gland releases the following hormones. ADH (antidiuretic hormone) - stimulates the kidneys to reabsorb fluid and produce less urine; Oxytocin - initiates labor, uterine contractions, and milk ejection in mothers.

In hypopituitarism, there is a lack of one or more pituitary hormones. Lack of a hormone leads to loss of function in the gland or organ the hormone controls. For example, lack of TSH leads to loss of normal function of the thyroid gland.

Hypopituitarism may be caused by:

  • Brain surgery
  • Brain tumor
  • Head trauma (traumatic brain injury)
  • Infections or inflammation of the brain and the tissues that support the brain
  • Death of an area of tissue in the pituitary gland (pituitary apoplexy)
  • Radiation therapy to the brain
  • Stroke (rare)
  • Subarachnoid hemorrhage (from a burst aneurysm)
  • Tumors of the pituitary gland or hypothalamus

Sometimes, hypopituitarism is due to uncommon immune system or metabolic diseases, such as:

  • Too much iron in the body (hemochromatosis)
  • Abnormal increase in immune cells called histiocytes (histiocytoses)
  • Autoimmune condition that causes inflammation of the pituitary (lymphocytic hypophysitis)
  • Sarcoidosis, a condition that causes inflammation of various tissues and organs
  • Infections of the pituitary, such as primary pituitary tuberculosis

Hypopituitarism is also a rare complication caused by severe bleeding during pregnancy. The loss of blood leads to tissue death in the pituitary gland. This condition is called Sheehan syndrome.

Certain medicines can also suppress pituitary function. The most common medicines are glucocorticoids (such as prednisone and dexamethasone), which are taken for inflammatory and immune conditions. Medicines used to treat prostate cancer can also lead to low pituitary function.

Symptoms

Symptoms of hypopituitarism include any of the following (multiple symptoms are common):

  • Abdominal pain
  • Decreased appetite
  • Lack of sex drive (libido) in men or women
  • Dizziness or fainting
  • Erection problems
  • Excessive urination and thirst (including frequent urination at night)
  • Failure to release milk (in women)
  • Fatigue, weakness
  • Headache
  • Infertility
  • Irregular or absent menstrual periods
  • Loss of armpit or pubic hair
  • Loss of the body or facial hair (in men)
  • Low blood pressure
  • Low blood sugar
  • Sensitivity to cold
  • Short height (less than 5 feet or 1.5 meters) if onset is during the childhood growth period
  • Slowed growth and sexual development (in children)
  • Vision problems
  • Weight loss

Symptoms may develop slowly and may vary greatly, depending upon:

  • The number of hormones that are missing and the organs they affect
  • The severity of the disorder

Other symptoms that may occur with this condition:

Exams and Tests

To diagnose hypopituitarism, there must be low hormone levels due to a problem with the pituitary gland. The diagnosis must also rule out diseases of the organ that is affected by this hormone.

Tests may include:

The level of a pituitary hormone may be high in the bloodstream if you have a pituitary tumor that is producing too much of that hormone. The tumor may compress other cells of the pituitary, leading to low levels of other hormones.

Treatment

If hypopituitarism is caused by a tumor, you may need surgery to remove the tumor. Radiation therapy may also be needed.

You will need lifelong hormone medicines to replace hormones that are no longer made by organs under the control of the pituitary gland. These may include:

  • Corticosteroids (cortisol)
  • Growth hormone
  • Sex hormones (testosterone for men and estrogen for women)
  • Thyroid hormone
  • Desmopressin

Medicines are also available to treat related infertility in men and women.

If you take glucocorticoid medicines for pituitary ACTH deficiency, be sure you know when to take a stress dose of your medicine. Discuss this with your health care provider.

Always carry a medical ID (card, bracelet, or necklace) that says you have adrenal insufficiency. The ID should also say the type of medicine and dosage you need in case of an emergency caused by adrenal insufficiency.

Outlook (Prognosis)

Hypopituitarism is usually permanent. It requires lifelong treatment with one or more medicines. But you can expect a normal life span.

In children, hypopituitarism due to a tumor may improve if the tumor is removed by surgery.

Possible Complications

Side effects of medicines to treat hypopituitarism can develop. However, do not stop any medicine on your own without talking with your provider first.

When to Contact a Medical Professional

Contact your provider if you develop symptoms of hypopituitarism.

Prevention

In most cases, the disorder is not preventable. Awareness of risk, such as from taking certain medicines, may allow early diagnosis and treatment.

Review Date: 5/12/2023

Reviewed By

Sandeep K. Dhaliwal, MD, board-certified in Diabetes, Endocrinology, and Metabolism, Springfield, VA. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.

References

Clemmons DR, Nieman LK. Approach to the patient with endocrine disease. In: Goldman L, Cooney KA, eds. Goldman-Cecil Medicine. 27th ed. Philadelphia, PA: Elsevier; 2024:chap 202.

Fleseriu M, Hashim IA, Karavitaki N, et al. Hormonal replacement in hypopituitarism in adults: an Endocrine Society clinical practice guideline. J Clin Endocrinol Metab. 2016;101(11):3888-3921. PMID: 27736313 pubmed.ncbi.nlm.nih.gov/27736313/.

Johannsson G, Ragnarsson O. Hypopituitarism including growth hormone deficiency. In: Robertson RP, ed. DeGroot's Endocrinology. 8th ed. Philadelphia, PA: Elsevier; 2023:chap 5.

Kaiser U, Ho K. Pituitary physiology and diagnostic evaluation. In: Melmed S, Auchus RJ, Goldfine AB, Koenig RJ, Rosen CJ, eds. Williams Textbook of Endocrinology. 14th ed. Philadelphia, PA: Elsevier; 2020:chap 8.

Disclaimer

The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. No warranty of any kind, either expressed or implied, is made as to the accuracy, reliability, timeliness, or correctness of any translations made by a third-party service of the information provided herein into any other language. © 1997- A.D.A.M., a business unit of Ebix, Inc. Any duplication or distribution of the information contained herein is strictly prohibited.

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Pituitary gland - Animation

The pituitary gland lies deep inside the head. It's often called the "master gland" because it controls many of the things other glands do.

Just above the pituitary is the hypothalamus. It sends hormonal or electrical signals to the pituitary. These determine which hormones the pituitary will release.

For example, the hypothalamus might send a hormone called GHRH, or growth hormone releasing hormone. That would trigger the pituitary's release of growth hormone, which affects the size of both muscle and bone.

How important is this? Not getting enough during childhood can cause pituitary dwarfism. Getting too much can cause the opposite condition called gigantism. In a body that has already matured, too much growth hormone can cause acromegaly. With this condition, facial features become rough and course; the voice becomes deeper; and hand, foot, and skull size expand.

A different hormonal command from the hypothalamus might trigger the release of thyroid stimulating hormone or TSH. TSH causes the thyroid to release two hormones called T3 and T4 that stimulate metabolism in other cells throughout the body.

The pituitary can also release a hormone called antidiuretic hormone, or ADH. It's produced in the hypothalamus and stored in the pituitary. ADH affects the production of urine. When it's released, the kidneys absorb more of the fluid that passes through them. That means less urine is produced.

Alcohol inhibits the release of ADH, so drinking alcoholic beverages results in more urine production.

The pituitary gland produces other hormones that control other bodily functions and processes.

For instance, follicle stimulating hormone, or FSH, and luteinizing hormone, or LH, are hormones that affect the ovaries and egg production in women. In men, they affect the testes and sperm production.

Prolactin is a hormone that affects breast tissue in nursing mothers.

ACTH or adrenocorticotrophic hormone causes the adrenal glands to produce important substances similar to steroids.

Growth, puberty, baldness, even sensations like hunger and thirst, are just a few of the processes that are influenced by the endocrine system.

 

Pituitary gland - Animation

The pituitary gland lies deep inside the head. It's often called the "master gland" because it controls many of the things other glands do.

Just above the pituitary is the hypothalamus. It sends hormonal or electrical signals to the pituitary. These determine which hormones the pituitary will release.

For example, the hypothalamus might send a hormone called GHRH, or growth hormone releasing hormone. That would trigger the pituitary's release of growth hormone, which affects the size of both muscle and bone.

How important is this? Not getting enough during childhood can cause pituitary dwarfism. Getting too much can cause the opposite condition called gigantism. In a body that has already matured, too much growth hormone can cause acromegaly. With this condition, facial features become rough and course; the voice becomes deeper; and hand, foot, and skull size expand.

A different hormonal command from the hypothalamus might trigger the release of thyroid stimulating hormone or TSH. TSH causes the thyroid to release two hormones called T3 and T4 that stimulate metabolism in other cells throughout the body.

The pituitary can also release a hormone called antidiuretic hormone, or ADH. It's produced in the hypothalamus and stored in the pituitary. ADH affects the production of urine. When it's released, the kidneys absorb more of the fluid that passes through them. That means less urine is produced.

Alcohol inhibits the release of ADH, so drinking alcoholic beverages results in more urine production.

The pituitary gland produces other hormones that control other bodily functions and processes.

For instance, follicle stimulating hormone, or FSH, and luteinizing hormone, or LH, are hormones that affect the ovaries and egg production in women. In men, they affect the testes and sperm production.

Prolactin is a hormone that affects breast tissue in nursing mothers.

ACTH or adrenocorticotrophic hormone causes the adrenal glands to produce important substances similar to steroids.

Growth, puberty, baldness, even sensations like hunger and thirst, are just a few of the processes that are influenced by the endocrine system.

 
 
 
 

 

 
 
 
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