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 affect 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

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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
• Metastatic cancer from lung, colon, prostate, or melanoma
• Uncommon immune system or metabolic diseases
• Sheehan syndrome—A rare complication after pregnancy

Risk Factors

Things that may raise the risk of this problem are:

• 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 slowly. They can be hard to recognize since they affect so many systems in the body. Some changes based on specific hormones are:

• 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 features—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
• Antidiuretic hormone deficiency (rare change) may cause:
  • Excessive thirst and urinating often
  • Nighttime urination

Diagnosis

The doctor will ask about your symptoms and health history. A physical exam will be done. You may need to see a doctor who treats hormone disorders.

Blood tests may be done to measure levels of hormones made by:

• The pituitary gland
• Glands that 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

The goal of treatment is to balance hormones. It will likely be needed for life. Some choices are:

• Hormone replacement therapy to replace missing hormones
• Treating the cause, such as a removing a tumor through medicine or surgery

Prevention

There are no known guidelines to prevent this health problem.