DIABETES AND ENDOCRINE SYSTEM Endocrine System • Graves' disease • Hypoglycemia • Goiter • Male hypogonadism • Gestational diabetes • Type 1 diabetes • Hyperthyroidism • Hypothyroidism • Addison's disease • Hyperparathyroidism • Diabetic retinopathy • Cushing's syndrome • Acromegaly • Hypopituitarism • Thyroid nodules • Metabolic syndrome • Prolactinoma • Pituitary tumors • Dehydration • Primary aldosteronism • Hashimoto's disease • Pheochromocytoma • Type 2 diabetes • Prediabetes • Diabetic coma • Diabetic hyperosmolar syndrome • Diabetic ketoacidosis • Diabetes insipidus

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Hypopituitarism is a disorder in which your pituitary gland fails to produce one or more of its hormones, or doesn't produce enough of them.

The pituitary is a small bean-shaped gland located at the base of your brain, somewhat behind your nose and between your ears. Despite its size, this gland secretes hormones that influence nearly every part of your body.

In hypopituitarism, you have a short supply of one or more of these pituitary hormones. This deficiency can affect any number of your body's routine functions, such as growth, blood pressure and reproduction.

Hypopituitarism is a rare disorder. Treatment for hypopituitarism involves taking hormone replacement medications.

Hypopituitarism is often progressive. Although the signs and symptoms can occur suddenly, usually they tend to develop gradually. They are sometimes vague and subtle and may be overlooked for many months or even years.

Signs and symptoms of hypopituitarism vary, depending on which pituitary hormones are deficient. The signs and symptoms may include:

• Fatigue
• A decline in energy
• Muscle weakness
• Nausea
• Constipation
• Weight loss or gain
• A decline in appetite
• Abdominal discomfort
• Sensitivity to cold or difficulty staying warm
• Visual disturbances
• Loss of underarm and pubic hair
• Joint stiffness
• Hoarseness
• Facial puffiness
• Thirst and excess urination
• Low blood pressure
• Headaches

If you're a man, you may also have signs and symptoms such as:

• Loss of interest in sexual activity
• Erectile dysfunction
• Decrease in facial or body hair

If you're a woman, you may develop:

• Irregular or stopped menstrual periods
• Infertility
• Inability to produce milk for breast-feeding

Children may experience stunted growth, short stature and slowed sexual development.

The pituitary gland is part of your endocrine system, which consists of glands that produce hormones that regulate processes throughout your body. The hormones secreted by the pituitary gland help regulate important functions such as growth, blood pressure and reproduction. For example, the pituitary secretes:

• Growth hormone (GH). This hormone controls bone and tissue growth and maintains the appropriate balance of muscle and fat tissue.
• Anti-diuretic hormone (ADH). By regulating urine production, this hormone manages water balance in your body. A deficiency of ADH results in a condition called diabetes insipidus, causing excess urination and thirst.
• Thyroid-stimulating hormone (TSH). This hormone stimulates your thyroid gland to produce key hormones that regulate your metabolism. Shortage of TSH results in an underactive thyroid gland (hypothyroidism).
• Luteinizing hormone (LH). In men, LH regulates testosterone production. In women, it fosters production of estrogen.
• Follicle-stimulating hormone (FSH). Working in tandem with LH, FSH helps stimulate sperm production in men and egg development and ovulation in women.
• Adrenocorticotropic hormone (ACTH). This hormone stimulates your adrenal glands to produce cortisol and other hormones. Cortisol helps your body deal with stress and influences many body functions, affecting blood pressure, heart function and your immune system.
• Prolactin. This hormone regulates the development of female breasts, as well as the production of breast milk.

Hypopituitarism is frequently triggered by a tumor of the pituitary gland. As pituitary tumors increase in size they can compress and damage pituitary tissue, interfering with hormone production. A tumor can also compress the optic nerves, causing visual disturbances.

The cause of hypopituitarism can also be other diseases and events that damage the pituitary, such as:

• Head injuries
• Brain tumor
• Brain surgery
• Radiation treatment
• Autoimmune inflammation (hypophysitis)
• Stroke
• Infections of the brain, such as meningitis
• Tuberculosis
• Infiltrative diseases, such as sarcoidosis, which is an inflammatory disease occurring in various organs; histiocytosis X, in which abnormal cells cause scarring in numerous parts of the body, such as the lungs and bones; and hemochromatosis, which causes excess iron deposition 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 hypopituitarism)
• Genetic mutations resulting in impaired pituitary hormone production

Diseases of the hypothalamus, a portion of the brain located just above the pituitary, also can cause hypopituitarism. The hypothalamus produces hormones of its own that directly affect the activity of the pituitary.

In some cases, the cause of hypopituitarism is unknown.

If you develop signs and symptoms associated with hypopituitarism, see your doctor to determine the cause.

Also, if certain symptoms of hypopituitarism develop suddenly — a severe headache or visual disturbances, confusion or drop in blood pressure — contact your doctor immediately. Such symptoms could represent sudden bleeding into the pituitary (pituitary apoplexy), which requires prompt medical attention.

If your doctor suspects a pituitary disorder, he or she will likely order several tests to check levels of various hormones in your body. Your doctor may also want to check for hypopituitarism if you've had a recent head injury that might have put you at risk of damage to your pituitary gland.

Blood tests can help detect deficits in hormones as a result of pituitary failure. For example, these tests can identify low levels of thyroid, adrenal or sex hormones, and determine that these low levels are associated with inadequate pituitary hormone production.

Your doctor may also suggest that you go to a specialized endocrine clinic to undergo stimulation or dynamic testing. These tests check your body's secretion of hormones after you've taken certain medications that can stimulate hormone production.

Your doctor may also recommend:

• Brain imaging. A computerized tomography (CT) or magnetic resonance imaging (MRI) scan of your brain can detect a pituitary tumor or other structural abnormality.
• Vision tests. These tests can determine if growth of a pituitary tumor has impaired your sight or visual fields.
• X-ray. In children, an X-ray of the hand and wrist can measure whether the bones are growing normally.

Successful treatment of the underlying condition causing hypopituitarism may lead to a complete or partial recovery of your body's normal production of pituitary hormones. The usual treatment for pituitary tumors is surgery to remove the growth. In some instances, doctors also recommend radiation treatment.

If hormone deficiencies persist after treatment, then you'll need prescriptions of one or more hormone replacement medications. These drugs are considered as "replacement" rather than treatment, because the dosages are set to match the amounts that your body would normally manufacture if it didn't have a pituitary problem. Treatment is usually lifelong.

Hormone replacement medications may include:

• Corticosteroids. These drugs, such as hydrocortisone or prednisone, 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 replaces deficient thyroid hormone levels caused by low or deficient TSH production.
• Sex hormones. These include testosterone in men and estrogen or a combination of estrogen and progesterone in women. Testosterone is administered through the skin with either a patch, a gel or by injection. Female hormone replacement can be administered with either pills or patches.
• Desmopressin (DDAVP). You take these hormones to replace ADH and to reduce your body's loss of water through frequent urination. This is taken by nasal spray or pills.
• Growth hormone. Also called somatropin, growth hormone is taken through an injection beneath your skin. It promotes growth, thus producing more normal height in children. Adults with a growth hormone deficiency may also benefit from growth hormone replacement, but they won't become taller.

If you've become infertile, preparations containing LH and FSH, also called gonadotropins, can be administered by injection to stimulate ovulation in women and sperm production in men.

A doctor who specializes in endocrine disorders (endocrinologist) may regularly monitor the levels of these hormones in your blood to ensure you're getting adequate — but not excessive — amounts of these hormones.

Your doctor will advise you to adjust your dosage of corticosteroids if you become seriously ill or experience major physical stress. During these times, your body would ordinarily produce extra cortisol hormone. The same kind of fine-tuning of dosage may be necessary when you have the flu, experience diarrhea or vomiting, or have surgery or dental procedures. Adjustments in dosage may also be necessary during pregnancy or with marked changes in weight. You may need periodic CT or MRI scans as well to monitor a pituitary tumor or other diseases causing the hypopituitarism.

Wear a medical alert bracelet or pendant, and carry a special card, notifying others — in emergency situations, for example — that you're taking corticosteroids and other medications.