Hypopituitarism

Overview 

What is hypopituitarism?

Hypopituitarism is a rare disorder of the pituitary gland. It is caused when the pituitary gland is underactive. It fails to produce one or more hormones, or doesn’t produce enough hormones. The change in hormone levels can cause a wide range of symptoms. Symptoms will depend on which hormone is deficient. 

The pituitary gland is part of your endocrine system. It includes all the glands that produce and regulate hormones. The pituitary gland is a small gland at the base of your brain, behind your nose. It influences almost every function of your body by controlling the production and release of most of the body’s hormones. Pituitary hormones regulate growth, blood pressure, reproduction and many other bodily functions. 

Treatment may be surgical removal of pituitary tumors, and replacing the hormones that are in short supply. Replacing hormones will stop or lessen your symptoms.

Causes

What’s the most common cause of hypopituitarism? 

The most common cause is a pituitary gland tumor. As it grows, it can compress and damage the gland, and cause problems with hormone production. 

Can hypopituitarism have other causes? 

It can be caused by a number of problems:

• Head injury or trauma  
• Brain infections such as meningitis, or tuberculosis or syphilis that spread to the brain
• Brain surgery
• Brain hemorrhage, causing bleeding into the brain or pituitary gland
• Stroke that interrupts blood flow to the brain or pituitary gland
• Inadequate blood supply to the pituitary gland, caused by anemia, blood clots or severe bleeding 

• Radiation treatment to the head or neck
• Medications, including high-dose corticosteroids, narcotics, and some cancer drugs
• Inflamed pituitary gland
• Certain diseases that affect multiple parts of the body
• Severe blood loss during childbirth that can damage part of the pituitary gland
• Inherited genetic changes
• Tumor on the hypothalamus — its hormones directly affect pituitary gland activity
• Hypothalamus problems, including inflammatory disorders, or insufficient hypothalamic hormones 
• Unknown causes

Symptoms

What causes hypopituitarism symptoms?

It’s more common for symptoms to occur when there’s a reduction in several hormones at the same time. Deficiency of just one hormone is rarer. 

What are the symptoms of hypopituitarism?

Initially you may not notice any symptoms because they develop slowly. With time, symptoms will worsen. However, a few patients develop symptoms suddenly. 

Symptoms caused by a pituitary tumor can include:

• Pituitary apoplexy, caused by swelling or blocked blood flow to the pituitary gland, results in bleeding and tissue destruction. Other symptoms include severe headache, stiff neck, fever, visual problems, and sleepiness or coma.

Specific symptoms depend on which hormones are affected and how much they’re affected:

• Growth hormone deficiency can cause growth problems in children, resulting in short height. In adults, it rarely causes symptoms. If symptoms occur, they can include low energy, muscle weakness, and changes in body fat/muscle composition and cholesterol levels. Adults with this deficiency may also socially isolate themselves and have a lack of ambition. 
• Deficiency of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) affect the reproductive system. Children may experience delayed puberty. Adult women may have a reduction in egg and estrogen production, hot flashes, irregular periods, loss of pubic hair, vaginal dryness, and inability to produce milk after childbirth. Men can have less sperm and testosterone production, erectile dysfunction, less body hair and mood changes. Both sexes may have a lower sex drive, infertility and fatigue.
• Deficiency in thyroid-stimulating hormone can produce symptoms such as fatigue, weight gain, dry skin, constipation, confusion, temperature sensitivity or difficulty staying warm.
• Adrenocorticotropic (ACTH) hormone makes the adrenal glands work correctly. If deficient, it can cause Addison’s disease, severe fatigue, frequent infections, low blood pressure, fainting, confusion, low blood sugar, low stress tolerance, and stomach pain with nausea or vomiting. As the most serious pituitary hormone deficiency, it can cause death if the body cannot make ACTH.
• Antidiuretic hormone deficiency can disrupt the body’s ability to balance its fluid levels. It can cause diabetes insipidus, resulting in excessive thirst and urination, and electrolyte imbalance.
• Prolactin deficiency interrupts the production of breast milk in new mothers.

What are the symptoms of hypothalamus hormone deficiency?

The hypothalamus produces hormones and nerve impulses that control the pituitary gland. If tumors affect the hypothalamus, it may not produce enough hormones. If your hypothalamus is causing hypopituitarism, you may have problems with appetite control, leading to obesity.

Diagnosis

How is hypopituitarism diagnosed?

Diagnosis begins by measuring blood levels of the pituitary gland hormones, and levels of hormones produced by the organs suspected of being deficient. Because the pituitary gland stimulates other glands, it can cause a deficiency of hormones produced by other glands. If several glands are underactive, hypopituitarism is often the cause. 

After a hypopituitarism diagnosis is made, the pituitary gland is evaluated with an MRI or CT to look for structural problems. These can include abnormal tissue growth, or enlargement or shrinkage of the pituitary gland.

Treatments

Can hypopituitarism be treated?

Yes. Treatment focuses on both correcting the reason why the pituitary gland is not producing sufficient hormones, and on replacing hormones that are deficient. 

What are common treatments for hypopituitarism?

Because the most common cause is a tumor, surgical removal of the tumor is the most common treatment. Surgery can reduce or eliminate pressure symptoms such as vision problems. 

Radiation therapy may be used to destroy any remaining tumor cells that couldn’t be removed with surgery. Radiation treatment usually slows the normal functioning of the pituitary gland. Your doctor will want you to have your pituitary gland evaluated regularly for at least 10 years after treatment. 

Will I need hormone replacement?

Most likely you will need to take synthetic hormones to compensate for the glands that aren’t producing enough hormones.

Call for an appointment with the specialists at Inland Endocrine today.

References

Mayo Clinic. 2021. Hypopituitarism. Patient Care & Health Information. Retrieved 07/05/2021, {https://www.mayoclinic.org/diseases-conditions/hypopituitarism/symptoms-causes/syc-20351645}

Carmichael, J.D., MD. 2021. Hypopituitarism. Merck Manual. Retrieved 7-5-2021,

{https://www.merckmanuals.com/home/hormonal-and-metabolic-disorders/pituitary-gland-disorders/hypopituitarism}

Cedars Sinai. 2020. Hypopituitarism. Cedars Sinai Health Library. Retrieved 7-5-2021,

{https://www.cedars-sinai.org/health-library/diseases-and-conditions/h/hypopituitarism.html}