It is a general term that refers to anyone depending on the pituitary gland.
This is a clinical definition used by endocrinologists and is interpreted in that one or more pituitary gland functions are deficient.
The term may refer to anterior and posterior failure of the pituitary gland.
The function of the deficient pituitary gland can result from damage to the pituitary or the area just above the pituitary, the hypothalamus. The hypothalamus contains releasing and inhibits hormones that control the pituitary gland.
Because these hormones are necessary for normal pituitary function, damage to the hypothalamus can also result in pituitary gland function deficiency.
Pituitary injury can occur from various problems, including damage to a pituitary tumor due to enlargement, pituitary irradiation, pituitary apoplexy, trauma, and abnormal iron storage (hemochromatosis). With increasing damage, there is a progressive decrease in function.
There seems to be a predictable loss of hormonal function with increasing damage.
The progression from the most vulnerable to the least susceptible is usually the following:
- Growth hormone.
- Gonadotropins (LH and FSH that control sexual/reproductive function), followed by TSH (which contains the release of the hormone thyroid).
- The last one holds the adrenal function.
Sheehan syndrome is a condition that can occur in a woman who has severe uterine bleeding during delivery.
The resulting severe blood loss causes the death of the tissue in your pituitary gland and leads to hypopituitarism after birth.
ACTH and Cortisol deficiency
The ACTH deficiency that results in cortisol deficiency is the most dangerous and life-threatening of the hormone deficiency syndromes.
With the gradual onset of the deficiency for days or weeks, the symptoms are often vague and may include weight loss, fatigue, weakness, depression, apathy, nausea, vomiting, anorexia, and hyperpigmentation.
As the deficiency becomes more severe or has a more rapid onset (Addison’s crisis), the symptoms may include confusion, stupor, psychosis, abnormal electrolytes (low serum sodium, elevated serum potassium), and vascular collapse (low blood pressure and shock) that can be fatal.
Treatment involves the administration of cortisol or another similar steroid (such as prednisone).
For patients with acute adrenal insufficiency (Addison’s crisis), rapid intravenous administration of steroids in high doses is essential to reverse the situation.
TSH and thyroid hormone deficiency
Thyroid hormone deficiency causes a syndrome that consists of decreased energy, increased need for sleep, intolerance to cold (inability to stay warm), dry skin, constipation, muscle pain, and decreased mental functions.
This constellation of symptoms is very uncomfortable and is often the complex of symptoms that drives patients with the pituitary disease to seek medical attention.
The replacement therapy consists of a daily pill called thyroxine. Blood tests determine the correct dose.
What is an underactive hypophyseal gland?
Your pituitary gland is at the bottom of your brain; it releases eight hormones, and each of these hormones plays its role in the function of your body.
The functions range from stimulating bone growth to stimulating the thyroid gland to release hormones that control your metabolism.
Hormones produced by the pituitary gland include:
- The adrenocorticotropic hormone triggers the production of cortisol and triggers the chemical reaction that causes your body to produce adrenaline and noradrenaline.
- The antidiuretic hormone controls your blood pressure and keeps the fluids in your body.
- The follicle-stimulating hormone stimulates the growth of the ovarian follicles in women and the production of sperm in men.
- Growth hormone causes children to grow and maintain body structure and metabolism in adults.
- Luteinizing hormone is responsible for fertility, puberty, and menstruation in women.
- Oxytocin is essential in childbirth and lactation. It can also play a crucial role in human behavior.
- Prolactin has more than 300 uses in the body.
- The thyroid-stimulating hormone regulates the production of hormones in the thyroid.
What causes an insufficient hypophyseal gland or hypopituitarism
Your pituitary gland may stop producing enough of one or more hormones if you have suffered a trauma. For example, if you have had brain surgery, a brain infection, or a head injury, your pituitary gland may be affected.
Certain tumors can also affect the function of this gland. These include:
- Brain tumors of the pituitary gland (a common cause of hypopituitarism).
- Tumors of the hypothalamus.
Other possible causes of hypopituitarism include:
- Sarcoidosis (a chronic lung disease).
- Hemochromatosis (a hereditary disease characterized by excess iron in the body).
- Histiocytosis X (a rare autoimmune disorder in which immune cells attack organs).
- Lymphocytic hypophysitis (an autoimmune disease characterized by inflammation of the pituitary gland).
- Loss of blood during childbirth (Sheehan syndrome).
- Radiation treatments.
- Sometimes, doctors can not know what caused a particular case of hypopituitarism.
The symptoms of hypopituitarism depend on which hormones your pituitary gland is not producing enough.
For example, if the pituitary does not produce enough growth hormone in a child, they may have a permanently low stature. Alternatively, if it does not produce enough follicle-stimulating hormone or luteinizing hormone, it could cause problems with sexual function, menstruation, and fertility.
If your doctor thinks you may have hypopituitarism, you will use a blood test to check the levels of the hormones produced by the pituitary gland. Sometimes, you will also check if your pituitary gland stimulates other glands.
For example, your doctor can check your T4 levels. Your pituitary gland does not produce this hormone. However, it releases TSH, which stimulates the thyroid gland to release T4. Therefore, having low levels of T4 indicates that you may have a problem with your pituitary gland.
Your doctor can prescribe specific medications before doing blood tests.
These medications are designed to stimulate the production of specific hormones in your body. You are taking these before the test can help your doctor get a better understanding of your pituitary gland function.
Once your doctor has determined that hormone levels are low, you should check the parts of your body affected by those hormones. Sometimes, the problem is not with your pituitary gland but with these other target organs.