Hypopituitarism

The signs and symptoms of hypopituitarism usually develop gradually and get worse over time. They are sometimes subtle and may be overlooked for months or even years. But for some people, signs and symptoms develop suddenly.

Signs and symptoms of hypopituitarism vary from person to person, depending on which pituitary hormones are affected and to what degree. In people who have more than one pituitary hormone deficiency, the second deficiency may increase or, in some cases, hide the symptoms of the first deficiency.

Growth hormone (GH) deficiency

In children, GH deficiency may cause growth problems and short stature. Most adults who have GH deficiency don't have any symptoms, but for some adults it can cause:

• Fatigue
• Muscle weakness
• Changes in body fat composition
• Lack of ambition
• Social isolation

Hypopituitarism has a number of causes. In many cases, hypopituitarism is caused by a tumor of the pituitary gland. As a pituitary tumor increases in size, it can compress and damage pituitary tissue, interfering with hormone production. A tumor can also compress the optic nerves, causing visual disturbances.

In addition to tumors, certain diseases or events that cause damage to the pituitary gland may also trigger hypopituitarism. Examples include:

• Head injuries
• Brain surgery
• Radiation treatment to the head or neck
• Lack of blood flow to the brain or pituitary gland (stroke) or bleeding (hemorrhage) into the brain or pituitary gland
• Certain medications, such as narcotics, high-dose corticosteroids or certain cancer drugs called checkpoint inhibitors
• Inflammation of the pituitary gland caused by an abnormal immune system response (hypophysitis)
• Infections of the brain, such as meningitis, or infections that can spread to the brain, such as tuberculosis or syphilis
• Infiltrative diseases, which affect multiple parts of the body, including sarcoidosis, an inflammatory disease occurring in various organs; Langerhans cell histiocytosis, in which abnormal cells cause scarring in numerous parts of the body; and hemochromatosis, which causes excess iron deposits in the liver and other tissues
• Severe loss of blood during childbirth, which may cause damage to the front part of the pituitary gland (Sheehan's syndrome or postpartum pituitary necrosis)

In some cases, hypopituitarism is caused by a genetic mutation (inherited). These mutations affect the pituitary gland's ability to produce one or more of its hormones, often starting at birth or in early childhood.

Tumors or diseases of the hypothalamus, a portion of the brain situated just above the pituitary, also can cause hypopituitarism. The hypothalamus produces hormones of its own that directly affect the activity of the pituitary gland.

If your doctor suspects a problem with your pituitary hormones, he or she will likely order several tests to check hormone levels in your body and search for a cause.

Your doctor may order tests including:

• Blood tests. These tests measure your hormone levels. For example, blood tests can identify low levels of thyroid, adrenal or sex hormones. The tests can determine if these low levels are associated with pituitary hormone production.
• Stimulation or dynamic testing. These tests also measure your hormone levels. Your doctor may suggest that you go to a clinic that specializes in endocrine conditions for these tests. These tests check your body's hormone levels after you've taken certain medications to stimulate hormone production.
• Brain imaging. Magnetic resonance imaging (MRI) or high-resolution computerized tomography (CT) of your brain can detect a pituitary tumor or other pituitary gland problems.
• Vision tests. These tests can determine if growth of a pituitary tumor has impaired your sight or visual fields.

The first step in treating hypopituitarism is often medication to help your hormone levels return to normal. This is usually called hormone replacement, because the dosages are set to match the amounts that your body would produce if it didn't have a pituitary problem. You may need to take the medication for the rest of your life.

In some cases, treatment of the condition causing hypopituitarism may lead to a complete or partial recovery of your body's ability to produce pituitary hormones.

Medications:

Hormone replacement medications may include:

• Corticosteroids. These drugs, such as hydrocortisone (Cortef) or prednisone (Rayos), replace the adrenal hormones that aren't being produced because of an adrenocorticotropic hormone (ACTH) deficiency. You take them by mouth.
• Levothyroxine (Levoxyl, Synthroid, others). This medication treats the low thyroid hormone levels (hypothyroidism) that a thyroid-stimulating hormone (TSH) deficiency can cause.
• Sex hormones. These include testosterone in men and estrogen or a combination of estrogen and progesterone in women. Testosterone is administered either by injection or through the skin with a patch or a gel. Female hormone replacement can be administered with pills, gels or patches.
• Growth hormone. Also called somatropin (Genotropin, Humatrope, others), growth hormone is administered through an injection beneath your skin. It promotes growth, which helps produce a more normal height in children. Adults with symptoms of growth hormone deficiency also may benefit from growth hormone replacement, but they won't grow taller.
• Fertility hormones. If you've become infertile, gonadotropins can be administered by injection to stimulate ovulation in women and sperm production in men.