Overview of hypopituitarism

Hypopituitarism refers to a deficiency of pituitary hormones. For a list of hormones secreted by the pituitary gland, and information about common aetiologies of pituitary disorders, see Introduction to pituitary disorders.

Hypopituitarism typically has nonspecific symptoms and an insidious onset. Acute hypopituitarism can occur if hormone deficiency remains untreated. In adults, symptoms of hypopituitarism include:

amenorrhoea
sexual dysfunction
fatigue
depression
altered mental state
cold intolerance
postural light-headedness.

Physical signs of hypopituitarism in adults include:

marked pallor
loss or lack of body hair
fine wrinkling of the face
delay in return of reflexes
testicular atrophy
orthostatic hypotension.

The symptoms and signs of hypopituitarism in children are different to those in adults, and depend on the age at presentation; they include:

hypoglycaemia—due to combined adrenocorticotrophic hormone (ACTH) and growth hormone deficiency
prolonged neonatal jaundice (giant-cell hepatitis)
micropenis
undescended testes in infancy
growth failure
delayed puberty.

Biochemical findings suggestive of hypopituitarism include:

low serum thyroxine (T₄) concentration in the absence of elevated serum thyroid stimulating hormone (TSH) concentration
in adults, low serum estrogen or androgen concentrations without elevated serum luteinising hormone or follicle stimulating hormone concentration.

In adults, hypopituitarism is commonly caused by a pituitary adenoma. The clinical history can be useful to identify hypopituitarism due to other causes—prior cranial radiotherapy increases the risk of hypopituitarism, often occurring years after radiotherapy. Head injury, subarachnoid haemorrhage and major postpartum haemorrhage can all precipitate hypopituitarism, for which the diagnosis is sometimes initially missed.

Genetic causes of hypopituitarism are usually detected during childhood. Hypopituitarism in a child can also occur following surgery or radiotherapy.