Health Library

Hypopituitarism

Definition

Hypopituitarism is when the pituitary gland does not make enough of one or more hormones. The pituitary gland is at the base of the brain. It makes hormones that effects how other glands in the body make hormones. This means hypopituitarism can cause lower levels of hormones from other glands as well.

The pituitary gland can affect:

  • Growth
  • Blood pressure
  • Sex organ function
  • Thyroid gland function
  • Breast milk production and other aspects of pregnancy and birth
  • Water balance in the body
  • Some reactions to stress
Pituitary Gland
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Causes

Hypopituitarism may be caused by one or more of the following:

  • Tumors of the pituitary gland, hypothalamus, or brain
  • Poor blood supply to the pituitary gland
  • Head trauma
  • Radiation therapy to the pituitary gland, head, or neck
  • Stroke
  • Infections and inflammatory diseases
  • Uncommon immune system or metabolic diseases
  • Sheehan syndrome—A rare complication after pregnancy
  • Metastatic cancer from lung , colon , prostate , or melanoma

Risk Factors

The risk of hypopituitarism is higher in those with:

  • History of childhood cancer—some treatments can damage the pituitary
  • Infections
  • Certain genetic changes
  • Type 1 diabetes
  • Sickle cell anemia
  • Reduced blood volume or hypovolemia

Symptoms

Symptoms often begin gradually. They can be hard to recognize since they affect so many systems in the body. Some changes based on specific hormones include:

  • Growth hormone deficiency may cause:
    • Poor overall growth
    • Short stature
    • Obesity
    • Muscle weakness
  • Thyroid-stimulating hormone deficiency may cause:
    • Sensitivity to cold
    • Weight gain
    • Constipation
    • Hair that is brittle and coarse
    • Slow heart rate
    • Dry skin
    • Muscle weakness or fatigue
  • Adrenocorticotropic hormone (ACTH) deficiency may cause:
    • Fatigue and weakness
    • Weight loss
    • Decrease in skin pigmentation
    • No menstruation in women of reproductive age
  • Follicle-stimulating hormone and luteinizing hormone deficiency may cause:
    • Infertility in men and women
    • Vaginal dryness
    • Loss of some gender-specific sexual characteristics—women may lose hair from their underarms, body, and pubic area
    • Reduced interest in sex
    • No menstruation in women of reproductive age
    • Problems keeping an erection
    • Muscle weakness
    • Small testes
    • Breast enlargement in men— gynecomastia
  • Antidiuretic hormone deficiency (rare change) may cause:
    • Excessive thirst and urinating often
    • Night-time urination

Diagnosis

The doctor will ask about symptoms and past health. A physical exam will be done. A specialist may be needed. Endocrinologists focus on hormone disorders. Blood tests may be done to measure:

  • Levels of hormones made by the pituitary gland
  • Levels of hormones made by glands, which are influenced by the pituitary gland

Medicine and hormones may be given. Blood tests will be given before and after they are given. Changes will help to test pituitary function.

An MRI scan of the brain may be done. They can show tumors or abnormal tissue, growth or shrinkage.

Treatment

Treatment can help to balance hormones. It will likely need to be treated for life. Treatment options include:

Hormone Replacement Therapy

Hormone medicine can help to replace the missing hormones. This medicine may not replace the pituitary hormone but the hormones of the target gland, such as the thyriod. The medicine helps to balance hormone and will stop or ease symptoms.

Treating Cause

Some hypopituitarism may be caused by a tumor on the pituitary gland. Removing the tumor may stop the hormone problems. Medicine may be used to try to reduce the tumor. Surgery may be needed to remove the tumor. Radiation may be used if surgery does not work.

Prevention

There are no prevention steps.

Resources

Pituitary Disorders Education and Support
http://www.pituitarydisorder.net

The Pituitary Society
https://pituitarysociety.org

Canadian Resources

Health Canada
https://www.canada.ca

Thyroid Foundation of Canada
http://www.thyroid.ca

References

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 Nov;101(11):3888

Higham CE, Johannsson G, Shalet SM. Hypopituitarism. Lancet. 2016 Nov 12;388(10058):2403-15.

Hypopituitarism. EBSCO DynaMed website. Available at: https://www.dynamed.com/condition/hypopituitarism . Accessed September 24, 2020.

Kim SY. Diagnosis and Treatment of Hypopituitarism. Endocrinol Metab (Seoul). 2015 Dec;30(4):443.