Who it affects
Hypopituitarism is an uncommon disorder affecting 45 per 100,000 people. Its causes include: surgical removal of a pituitary tumour, radiation of the pituitary, infections and tumours (usually benign).
What gland is involved
The pituitary gland is situated just below the brain and behind the nose. It is a small gland that has two lobes; anterior and posterior. The anterior lobe secretes hormones including TSH, ACTH, LH, FSH, GH and prolactin. Patients with hypopituitarism lack one or more of these hormones. Patients with panhypopituitarism lack all the hormones secreted by the pituitary gland. The posterior lobe secretes vassopressin.
Symptoms
The symptoms a particular patient may experience is dependent on which hormone(s) is lacking.
Symptoms associated with a lack of ACTH may include tiredness, lethargy, weight loss and dizziness.
Symptoms associated with a lack ofLH and FSH may result in absence or irregularity of the menstrual cycle, loss of libido, or infertility.
Symptoms associated with a lack of TSH may be associated with tiredness, weight gain, constipation and dry skin.
Symptoms associated with a lack ofprolactin is usually not associated with specific symptoms.
Symptoms associated with a lack ofgrowth hormone in adults may be associated with reduced muscle mass, bone mass, quality of life and cardiac function.
Symptoms associated with a lack of vassopressin include excess urination and subsequent thirst and excessive drinking of fluids.
Diagnosis
Hypopituitarism is diagnosed with blood tests. These may include the administration drugs such as insulin, glucagon or tetracosactrin, followed by a series of blood tests.
Treatment
Treatment is dependent on which hormone(s) is deficient. Replacement is often with the end hormone rather than the pituitary hormone itself. For example, TSH is produced by the pituitary and stimulates the thyroid to produce thyroxine. A deficiency in TSH is therefore treated with levothyroxine therapy. Similarly ACTH deficiency is treated with oral steroids, usually hydrocortisone in split doses.
Prognosis
Patients with hypopituitarism usually require life long replacement therapy. Once patients are on the correct replacement therapy, the majority of patients have a good quality of life and the outlook is very good.
