Hypopituitarism

Hypopituitarism is the failure of production of one or more hormones from the pituitary gland.

Hypopituitarism

Pituitary gland is a small gland placed at the brain base. Hypopituitarism is the failure of production of one or more hormones from the pituitary gland.

Alternative names for hypopituitarism

‘Hypopit’; pituitary insufficiency; partial hypopituitarism; panhypopituitarism (‘pan’ referring to all pituitary hormones being affected); anterior hypopituitarism

What is 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 either or both parts.

What causes hypopituitarism?

Below are listed some of the causes of hypopituitarism:

  • tumours either pituitary (these are nearly always benign) or non-pituitary e.g. craniopharyngioma and spreading cancer
  • treatments for pituitary tumours, for example, pituitary surgery or radiotherapy
  • damage to the blood supply of the pituitary gland due to blockage or bleeding (e.g. pituitary apoplexy)
  • injury or trauma to the head, or stroke
  • genetic errors meaning the pituitary gland cannot produce certain hormones, e.g. Kallmann’s syndrome
  • damage to the pituitary gland from surgery or radiation therapy to the head, as treatment for non-pituitary tumours e.g. for the treatment of leukaemia or brain tumours
  • inflammation of the pituitary gland (hypophysitis)
  • infiltration of the pituitary gland (histiocytosis X, or Langerhans cell histiocytosis)
  • infections such as tuberculosis
  • congenital diseases or malformations of the pituitary gland.
  • Idiopathic (no identifiable cause)

What are the signs and symptoms of hypopituitarism?

Hypopituitarism can range from being asymptomatic to collapse and coma. The signs and symptoms of hypopituitarism depend on which part of the pituitary gland is 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:

How common is hypopituitarism?

Hypopituitarism is rare. At any given time, between 300 and 455 people in a million may have hypopituitarism. Hypopituitarism is more common after special situations e.g. brain injuries and postpartum haemorrhage.

Is hypopituitarism inherited?

Most cases of hypopituitarism are not inherited. However, there are some very rare genetic abnormalities than can cause hypopituitarism.

How is hypopituitarism diagnosed?

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 hormones. These blood tests may be one-off samples or the patient may require more detailed testing on a day-unit. These are called ‘dynamic’ or ‘provocative’ tests and they measure hormone levels before and after stimulation to see if the pituitary gland is working properly.

If it is suspected that there is a lack of anti-diuretic hormone (as can be the case with Diabetes Insipidus), 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, urine tests and body weight. The test may be extended up 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.

How is hypopituitarism treated?

Hypopituitarism is treated by replacing the deficient hormones. Treatment will be tailored to the individual depending on which hormones they are deficient in:

Deficiency of adrenocorticotropic hormone and consequently, cortisol from the adrenal glands, is treated by replacing the cortisol with steroid tablets either hydrocortisone'>hydrocortisone or prednisolone; these are taken by mouth in doses to be taken twice or three times a day. In the event of other illness happening at the same time, the need to increase or double the dose of cortisol is of critical importance ‘sick day rules’. It is important to remember that cortisol is life-saving and people who take cortisol must carry a ‘steroid card’ and wear ‘Medic-alert’ jewellery.

Growth hormone can be replaced in some individuals by daily self-administered injections (see the article on adult-onset growth hormone deficiency).

Sex hormones are replaced in women by either taking the oral contraceptive pill or hormone replacement therapy. In men, testosterone is replaced using various manufactured forms of testosterone including patches, gels and injections based on people’s lifestyles and preferences. Testosterone tablets can be used in special cases. To try and restore fertility in men and women, special hormones given as injections are required with the assistance, sometimes, of a fertility specialist.

Deficiency of thyroid stimulating hormone and consequently thyroid hormones (thyroxine and triiodothyronine) is treated by taking levothyroxine tablets orally every day.

Anti-diuretic hormone is replaced by using a medicine called desmopressin which can be given as a nasal spray, tablet or injection.

Are there any risks to the treatment?

Since the treatment of hypopituitarism only involves replacing hormones that the body should be making but is unable to, there should be no risks 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. Careful monitoring and medical follow up are required to avoid the effects of either under or over replacement.

What are the longer-term implications of hypopituitarism?

Hypopituitarism can be transient in some cases. People with long-term hypopituitarism will need to take daily medication and will require regular checks with an endocrinologist at an outpatient’s clinic. They may require hospital admissions in emergency cases.

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, smoking cessation, a balanced diet and exercise 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, monitoring and follow up can reduce all these risks.


Last reviewed: Jan 2019