‘Hypopit’; pituitary insufficiency; partial hypopituitarism; panhypopituitarism (‘pan’ referring to all pituitary hormones being affected); anterior hypopituitarism
Hypopituitarism is failure of the pituitary gland to produce one, some, or all of the hormones it normally produces. The pituitary gland has two parts, the anterior pituitary and the posterior pituitary, and hormone production can be affected in both parts.
Below are listed some of the causes of hypopituitarism:
infiltration of the pituitary gland (histiocytosis X, or Langerhans cell histiocytosis)
The signs and symptoms of hypopituitarism depend on which of the pituitary gland hormones are involved, to what extent and for how long. It also depends on whether the hormone deficiencies began as a child or later in adult life. Symptoms can be slow at the start and vague. It is worth understanding the normal function and effects of these hormones in order to understand the signs and symptoms of hypopituitarism. (See the article on pituitary gland.) There may also be additional symptoms due to the underlying cause of the hypopituitarism, such as the effects of pressure from a tumour.
Symptoms can include:
Hypopituitarism is rare. At any given time, between 300 and 455 people in a million may have hypopituitarism. A number of endocrinologists believe that hypopituitarism is quite common after brain injuries. If this belief is confirmed, then hypopituitarism may be significantly more common than previously believed.
Most cases of hypopituitarism are not inherited. However, there are some very rare genetic abnormalities than can cause hypopituitarism.
Blood tests are required to check the level of the hormones, which are either produced by the pituitary gland itself, or by peripheral endocrine glands controlled by the pituitary gland. These blood tests may be one-off samples or the patient may require more detailed testing on a day-unit. These are called ‘dynamic’ tests and they measure hormone levels before and after stimulation to see if the normal pituitary gland is working properly. They usually last between 1 to 4 hours.
If it is suspected that there is a lack of anti-diuretic hormone, the doctor may organise a water deprivation test. The patient will be deprived of water for a period of eight hours under very close supervision with regular blood and urine tests. The test may be extended to a 24 hour period if needed, which means an overnight stay in hospital.
Other tests may also be organised to try and identify the underlying cause of the hypopituitarism. These could include blood tests, scans such as computerised tomography (CT) or magnetic resonance imaging (MRI) scans, and tests for vision.
Hypopituitarism is treated by replacing the deficient hormones. Treatment will be tailored to the individual depending on which hormones they are deficient in:
Since the treatment of hypopituitarism only involves replacing hormones that the body should be making but is unable to, there should be no side-effects if the appropriate amounts of hormones are replaced. Patients will be monitored to ensure they are receiving the correct amount of replacement hormones. Some side-effects can occur from hormone replacement if the amount replaced is higher than the individual’s body requirements. If the patient has any concerns, they should discuss them with their doctor.
People with long-term hypopituitarism will need to take daily medication and will require regular checks with an endocrinologist at an outpatient’s clinic.
People with hypopituitarism may have an impaired quality of life. Hypopituitarism is associated with an increased risk of heart disease and strokes as a result of the physical changes that occur in body fat, cholesterol and circulation. Healthy living, a balanced diet and exercise to prevent becoming overweight are essential to reduce this risk.
People with hypopituitarism also have a higher risk of developing osteoporosis or brittle bones and, therefore, have a higher risk of developing fractures from minor injuries. A diet that is rich in calcium and vitamin D along with moderate amounts of weight-bearing exercise and training are helpful in decreasing this risk.
Appropriate pituitary hormone replacement therapy can reduce all these risks.
Last reviewed: Jan 2015