What Is Hypopituitarism?
Hypopituitarism is a condition in which your pituitary gland (a small gland at the base of the brain) doesn’t make one or more of its hormones, or not enough of them. This condition may be the result of disease in the pituitary or hypothalamus (a part of the brain that contains hormones that control the pituitary gland). When there is low or no production of all the pituitary hormones, the condition is called panhypopituitarism. This condition may affect both children or adults.
The pituitary gland sends signals to other glands, for example the thyroid gland, to make hormones, such as thyroid hormone. The hormones made by the pituitary gland and other glands have a big impact on bodily functions, such as growth, reproduction, blood pressure, and metabolism. When one or more of these hormones isn’t produced as it should be, your body’s normal functions can be affected. Some of the problems with hormones, such as with cortisol or thyroid hormone, may need immediate treatment. Others aren’t life-threatening problems.
The pituitary gland makes several hormones. Some important ones include:
- Adrenocorticotropic hormone (ACTH) is a hormone that stimulates the adrenal glands (glands located above or on top of the kidneys that produce hormones). ACTH triggers the adrenal glands to release a hormone called cortisol, which regulates metabolism and blood pressure.
- Thyroid-stimulating hormone (TSH) is a hormone that stimulates production and secretion of thyroid hormones from the thyroid gland (a gland in the hormone system). Thyroid hormone regulates the body’s metabolism and is important in growth and development.
- Follicle-stimulating hormone (FSH) and luteinizing hormone (LH) are hormones that control sexual function in males and females. LH and FSH are also known as gonadotropins. They act on the ovaries or testes to stimulate sex hormone production- estrogen from ovaries and testosterone from testes.
- Growth hormone (GH) is a hormone that stimulates normal growth of bones and tissues.
- Prolactin is a hormone that stimulates milk production and female breast growth.
- Antidiuretic hormone (ADH) is a hormone that controls water loss by the kidneys.
- Oxytocin tells a woman’s uterus to contract during childbirth and signals milk to release so the baby can feed. It also helps sperm move in men. Oxytocin also plays a part in the parent-child bond, sexual arousal, and feelings of trust.
In hypopituitarism, one or more of these pituitary hormones is missing. The lack of hormone results in a loss of function of the gland or organ that it controls.
A loss of function in or damage to your pituitary gland or hypothalamus results in low or absent hormones. You might have this because of:
- Infections such as meningitis, or various other conditions.
- Head injuries
- Stroke or bleeding into the brain
- Inflammation caused by abnormal immune system response
- Severe loss of blood during childbirth
- Genetic mutation
In some cases, the cause is unknown.
Some people may have no symptoms or a gradual onset of symptoms. In other people, the symptoms may be sudden and dramatic. The symptoms depend on the cause, how fast they come on, and the hormone that is involved.
- ACTH deficiency: Symptoms include fatigue, low blood pressure, weight loss, weakness, depression, nausea, or vomiting.
- TSH deficiency: Symptoms include constipation, weight gain, sensitivity to cold, decreased energy, and muscle weakness or aching.
- FSH and LH deficiency: In women, symptoms include irregular or stopped menstrual periods and infertility. In men, symptoms include loss of body and facial hair, weakness, lack of interest in sexual activity, erectile dysfunction, and infertility.
- GH deficiency: In children, symptoms include short height, fat around the waist and in the face, and poor overall growth. In adults, symptoms include low energy, decreased strength and exercise tolerance, weight gain, decreased muscle mass, and feelings of anxiety or depression.
- Prolactin deficiency: In women, symptoms include lack of milk production. No symptoms are seen in men.
- ADH deficiency: Symptoms include increased thirst and urination.
- Oxytocin hormone deficiency: Women may have a hard time breastfeeding because of difficulty with milk letdown. Low oxytocin may also trigger symptoms of depression.
Call the doctor or health care practitioner if any of the above symptoms develop.
- ACTH (Cortrosyn) stimulation test
- TSH and thyroxine test
- FSH and LH and either estradiol or testosterone (whichever is appropriate for the patient)
- Prolactin test
- GH stimulation test
- Stimulation or suppression testing (tests that check your hormone levels after you take certain medications)
- Vision tests
You may get an MRI or CT scan of the pituitary gland may to find whether a tumor is present.
In children, X-rays of the hands may be taken to determine if bones are growing normally.
Medical treatment consists of hormone replacement therapy and treatment of the underlying cause.
Drugs used to treat hypopituitarism replace the hormone of which you don’t have enough:
- Glucocorticoids (for example, hydrocortisone) are used to treat adrenal insufficiency resulting from ACTH deficiency.
- Thyroid hormone replacement therapy is used for hypothyroidism (a condition in which thyroid production is low). Drugs, such as levothyroxine (for example, Synthroid, Levoxyl), may be used. In the drug’s active form, it influences growth and development of tissues.
- Sex hormone deficiency is treated with sex-appropriate hormones such as testosterone or estrogen.
- Testosterone replacement therapy (for example, Androderm) is used in men. Testosterone promotes and maintains the development of secondary sexual characteristics such as facial hair in males with androgen deficiency.
- Estrogen replacement therapy (for example, Premarin) with or without progesterone is used in women. Estrogens are important in developing and maintaining the female reproductive system and secondary sexual characteristics such as breast development.
- Growth hormone (GH) replacement therapy is used for children as appropriate. Growth hormone stimulates linear growth and growth of skeletal muscle and organs. GH therapy may also be used in adults, but it will not make them grow taller. Examples include somapacitan-beco (Sogroya) or somatropin (Humatrope or Genotropin).
- Fertility hormones such as gonadotropin can help jumpstart ovulation or sperm production if you’re dealing with infertility.
If a tumor is involved, you may need surgery, depending on its type and location.
If hormone replacement therapy works, the prognosis is good. Complications are often related to the underlying disease.
Checkups with the doctor or health care practitioner are important. The doctor may need to adjust the dose of hormone replacement therapy.