Definition

The pituitary gland is in the brain. It produces several important hormones that control the production of other hormones made by glands in the body.

The pituitary gland is responsible for many body functions, including the following:

    
  • Growth
  • Blood pressure
  • Sex organ function
  • Thyroid gland function
  • Breast milk production and other aspects of pregnancy and birth
  • Control of sugars and fats into energy or storage
  • Water balance in the body

    • Hypopituitarism is an insufficient production of one or more hormones. It is not a common disorder. A problem in the pituitary can cause the amount of hormones from other glands to diminish as well. This can be a serious and sometimes, life-threatening problem. It will require care from your doctor.

    Pituitary Gland

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    Causes

    There are several factors which may cause this condition:

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

    • Risk Factors

    Factors that increase your the chance for hypopituitarism include:

        
  • History of childhood cancer (treatment can damage the endocrine system, which controls hormones)
  • Infections
  • Genetics
  • Type 1 diabetes
  • Sickle cell anemia
  • Reduced blood volume or hypovolemia

    • Symptoms

    Symptoms often begin gradually and are not very specific since hormones control a variety of body functions. They may not be recognized for a while. Specific symptoms will depend on the type and level of hormone affected. For example:

        
  • Growth hormone deficiency:     
  • Poor overall growth
  • Short stature
  • Increased blood pressure
  • Central obesity
  • Muscle weakness
  • Small heart
  • Thyroid-stimulating hormone deficiency:     
  • Sensitivity to cold
  • Weight gain
  • Constipation
  • Hair that is brittle and coarse
  • Heart rate slowed
  • Dry skin
  • Muscle weakness or fatigue
  • Adrenocorticotropic hormone (ACTH) deficiency:     
  • Fatigue and weakness
  • Low blood pressure
  • Weight loss
  • Increase in skin pigmentation
  • Amenorrhea
  • Follicle-stimulating hormone and luteinizing hormone deficiency:     
  • 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 libido
  • Amenorrhea
  • Erectile dysfunction
  • Muscle weakness
  • Small testes
  • Breast enlargement in men

    • Diagnosis

    Your doctor will ask about your symptoms and medical history. A physical exam will be done. Your doctor may refer you to an endocrinologist. This is a type of doctor that focuses on hormone disorders.

    Tests to determine hypopituitarism include taking a blood sample to do the following:

        
  • Measure the levels of hormones produced by the pituitary gland
  • Measure the levels of hormones produced by target endocrine glands, which are influenced by the pituitary gland

    • Provocative tests of pituitary function may also be done such as:

        
  • Growth hormone-releasing hormone (GHRH) test
  • Arginine stimulation test
  • L-dopa
  • Clonidine stimulation test
  • Insulin tolerance test
  • Adrenocorticotropic hormone (ACTH) stimulation test

    • Once the diagnosis is confirmed:

        
  • Imaging tests (eg, an MRI )—to identify problems such as abnormal tissue and growth or shrinkage of the pituitary gland

    • Treatment

    Talk with your doctor about the best plan for you. This condition is likely permanent, though also depends on the cause. It will likely need to be treated for life. Treatment options include:

    Medications

    If the condition is caused by a tumor, it is first treated with medications such as:

        
  • Bromocriptine
  • Cabergoline
  • Octreotide

    • Surgery

    Medication may not always work. In this case, surgery may be needed. If a tumor is involved it will be removed. Part or all of the gland may be removed as well.

    Hormone replacement therapy is needed after surgery or if other hormone deficiencies are found.

    Hormone Replacement Therapy

    When the target hormone levels are inadequate, they must be replaced. In most cases, therapy does not replace the hormones that the pituitary gland produces. Instead, the hormones of the other target glands that it stimulates are replaced. Examples include:

        
  • Glucocorticoids (adrenal hormone) (eg, prednisone, hydrocortisone, dexamethasone)
  • Thyroid hormone (eg, levothyroxine)
  • Testosterone (male)—can be replaced with patches, gels, or injections
  • Estrogen and progesterone (female)—can be replaced with oral pill or patches
  • Growth hormone—usually a daily injection
  • Antidiuretic hormone (ADH)—can be given as pill, subcutaneous injection, or nasal puff

    • Radiation Therapy

    Treatment with radiation may be used after drug or surgical treatment or if they have failed.

    Prevention

    In general, this condition is not preventable. Be aware of the risks and symptoms. This will make early diagnosis and treatment possible.