Overview of hypopituitarism
Hypopituitarism is a rare disorder in which the pituitary gland either does not produce one or more hormones or does not produce enough hormones. The pituitary gland is the bean-sized gland located at the base of your brain. It is part of your body’s endocrine system, which contains all the glands that make and regulate hormones. Despite its small size, the pituitary gland produces and releases many hormones that work in almost every part of your body.
Hypopituitarism occurs when there is a shortage (deficiency) of one or more pituitary hormones. Deficiencies in these hormones can affect your body’s daily routine, such as growth, blood pressure, or reproduction. Symptoms usually vary depending on the hormone.
If you have hypopituitarism, you may need to take medicine for the rest of your life. Medications can help replace missing hormones, which can help control your symptoms.
What are the symptoms of hypopituitarism?
Some people may not have any symptoms. In other people, symptoms can be sudden and dramatic. The cause of the symptoms depends on how quickly they fall and the hormone involved.
ACTH deficiency: symptoms of 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 pain.
FSH and LH deficiency: In women, symptoms are irregular or stopped periods and infertility. In men, symptoms include loss of body and facial hair, weakness, loss of interest in sexual activity, erectile dysfunction, and infertility.
Prolactin deficiency: in women, symptoms of lack of milk production. Symptoms do not appear in men.
ADH deficiency: symptoms of increased thirst and urination.
Oxytocin hormone deficiency: It can be very difficult for women to breastfeed because they have trouble getting milk. Low oxytocin can also lead to depressive symptoms.
Causes of hypopituitarism
There are many causes of hypopituitarism. In many cases, hypopituitarism is caused by a tumour of the pituitary gland. As the pituitary tumour grows, it shrinks and damages the pituitary tissue, interrupting the production of hormones. A tumor can also contract the optic nerve, causing visual disturbances. In addition to tumours, certain diseases or events that cause damage to the pituitary gland can also trigger hypopituitarism. Examples:
- Head injuries
- Brain surgery
- Radiation therapy to the head or neck.
- Brain or pituitary gland (stroke) or haemorrhage (bleeding): Lack of blood flow to the brain or pituitary gland.
- Inflammation of the pituitary gland is caused by an abnormal response of the immune system (pituitary).
- Brain infections such as meningitis, and tuberculosis or syphilis.
Severe blood loss during childbirth, which can damage the anterior part of the pituitary gland.
In some cases, hypopituitarism is caused by a genetic mutation (inheritance). These mutations affect the ability of the pituitary gland to produce one or more hormones, which often begin at birth or childhood. Tumours or diseases of the hypothalamus, a part of the brain just above the pituitary, can also cause hypopituitarism. The hypothalamus produces its own hormones, which directly affect the activity of the pituitary gland. In some cases, the cause of hypopituitarism is unknown.
Diagnosis of hypopituitarism
If your doctor suspects a problem with your pituitary hormones, he may order various tests to check your body’s hormone levels and look for a cause. Your doctor may order tests that include:
- Blood test. These tests measure your hormone levels. For example, blood tests can detect low levels of thyroid, adrenal, or sex hormones. Tests can determine if these low levels are associated with the production of pituitary hormones.
- Stimulus or dynamic test. These tests also measure your hormone levels. Your doctor may recommend that you go to a clinic that specializes in endocrine conditions for these tests. These tests measure your body’s hormone levels after you have taken certain medications to stimulate hormone production.
- Vision tests. These tests can determine if the growth of a pituitary tumour is affecting your vision or visual fields.
How is hypopituitarism treated?
Medical treatment includes hormone replacement therapy and treatment of the underlying cause.
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). 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.
Monitoring and adjusting medications
A doctor who specializes in endocrine disorders (endocrinologist) can monitor your symptoms and the levels of these hormones in your blood to make sure you are getting the right amounts. If you are taking corticosteroids, you should work with your doctor to adjust the dose of your medication during physical or mental stress. During these times, your body usually makes extra cortisol hormones.
Surgery or other procedures
You may need regular CT scans or MRIs to monitor for pituitary tumours or other diseases that cause hypopituitarism. Treatment of pituitary tumours involves surgery to remove the growth. In some cases, radiation therapy or medications may be prescribed to control the underlying cause.
In case of emergency
If you have hypopituitarism, it’s important to wear a medical alert bracelet or pendant and carry a special card notifying others in emergencies, for example of your condition. This is especially important if you’re taking corticosteroids for an ACTH deficiency.
Key points about hypopituitarism
- Hypopituitarism happens when the pituitary gland is not active enough. It does not make enough hormones.
- Hypopituitarism can directly affect the pituitary gland or it can indirectly affect the gland through changes in the hypothalamus.
- Symptoms depend on which hormones the pituitary gland is not making enough.
- The goal of treatment is to return the pituitary gland to normal function. Treatment may include hormone replacement therapy, surgery to remove a tumour, or radiation therapy.