Hypopituitarism is a rare disorder that is defined by a decrease in or lack of secretion of one of the hormones normally produced by the pituitary gland which is a small gland located at the base of the brain.
Definition & Facts
Hypopituitarism involves a deficiency in one if not more of the hormones produced by the pituitary gland. It can affect a variety of the body's basic functions, including reproduction, blood pressure, and growth. Depending on the cause, hypopituitarism often requires a life-long regimen of medication to control symptoms.
Symptoms & Complaints
Symptoms and signs of hypopituitarism may vary, depending on which of the pituitary hormones are low and the severity of the deficiency. Symptoms of hypopituitarism may include:
- Irregular periods or no periods
- Lack of ability to produce breast milk in women
- Hot flashes
- Loss of body hair in men
- Stunted growth in children
- Unexplained weight loss
- Decreased sex drive
- Loss of pubic hair
- Sensitivity to cold
- Difficulty staying warm
- Loss of appetite
- Facial puffiness
While hypopituitarism can possibly be the result of certain inherited disorders, hypopituitarism is frequently brought on by a pituitary gland tumor. As a tumor of the pituitary gland gets bigger, it can potentially damage and compress pituitary tissue that may interfere with hormone production. The optic nerves may also be compressed by the tumor, causing visual disturbances.
Hypopituitarism can also be caused by diseases and events that may damage the pituitary gland, including:
- Infections of the brain
- Inflammation from autoimmune diseases
- Brain surgery
- Certain genetic mutations
- Hypothalamic diseases
- Head injuries
- Brain tumors
- Radiation treatment
Sometimes, the cause of hypopituitarism is unknown in which case it is said to be idiopathic.
Diagnosis & Tests
If an individual's doctor thinks that they may have a pituitary disorder, they will likely order a variety of tests in order to check the body's levels of different hormones. If the individual has recently had a traumatic head injury or radiation treatment that may have damaged the pituitary gland, the doctor may also want to do the necessary tests for hypopituitarism.
The doctor will likely run blood tests that help detect hormone deficiencies that may have resulted because of pituitary damage. Blood tests can find if the patient has low levels of thyroid hormones, sex hormones, or adrenal hormones, and may help in determining if these decreased levels are aligned with deficient production of the pituitary hormones.
The doctor may perform stimulation or dynamic testing for which they refer the patient to an endocrine clinic. These tests check secretion of hormones in the body after the patient has taken certain medications that may increase production of hormones.
Brain imaging may also be in order. An MRI of the brain can be useful to find a pituitary tumor or any other abnormality in the brain. Vision tests may also be conducted to see if pituitary tumor growth has affected the patient's visual acuity.
Treatment & Therapy
Treating the condition underlying the hypopituitarism may lead to total or some recovery of the regular production of pituitary hormones in the body. Treatment for pituitary tumors might involve surgery to remove any growths that are detected. In some cases, doctors also may suggest treatment involving radiation.
Often the first step is treatment with hormone replacement therapy. These drugs are considered "replacement" hormones because the dosages are made to replicate the amounts that the body would normally be making if it did not have a problem with the pituitary gland. Hormone replacement therapy can potentially last for the rest of a person's life. Hormone replacement drugs may include:
- Corticosteroids. Corticosteroids, like hydrocortisone or prednisone, replace certain adrenal hormones that the body isn't producing because of a deficiency in the adrenocorticotropic hormone. These are taken orally.
- Levothyroxine (Levoxyl®, Synthroid®). These drugs replace levels of the hormones produced by the thyroid that may be deficient. The deficiency may be caused by a lack of or decrease in production of TSH which the pituitary secretes.
- Sex hormones. Sex hormones include testosterone for men and for women, estrogen or a estrogen/progesterone combination. Testosterone may be taken via the skin with a gel or an injection or a patch. Replacement of female hormones can be taken orally with pills, or through the skin with gels or patches.
- Growth hormone. A growth hormone, also referred to as somatotropin, is administered by an injection under the skin. It enhances growth and assists with children with hypopituitarism to achieve a normal height. Adults with a deficiency in growth hormones may also benefit from replacing the growth hormone, but it will have no effect on height.
- If the individual has become infertile, gonadotropin may be taken by injection to stimulate sperm production in men and ovulation in women.
Hormone replacement therapy requires monitoring. An endocrinologist will monitor the levels of these hormones in the blood to make sure that the patient is getting necessary but not excessive amounts. The doctor may suggest that the patient change the dosage of corticosteroids if he or she ends up becoming very ill or if they experience serious physical stress. The body would normally produce an excess amount of cortisol hormone during these times.
The same kind of adjustment of dosage may also be needed when an individual has the flu, is experiencing diarrhea or vomiting, or if they have had surgery or any dental procedures. Dosage adjustments may also be necessary while the patient is pregnancy or or if they experience significant changes in weight. They may require CT or MRI scans periodically as well in order to keep an eye on a pituitary tumor or any other disease that may be causing the hypopituitarism.
Prevention & Prophylaxis
In these cases, regular follow-up with the doctor is very important. Individuals with hypopituitarism may want to consider wearing a medical alert bracelet or carrying an identity card with details of their disorder and the medicines that they take.