PassFinals
Endocrinology & Metabolic

Hypopituitarism

Hypopituitarism is deficiency of one or more pituitary hormones, producing secondary adrenal, thyroid, gonadal or growth-hormone failure; glucocorticoid deficiency is the immediate life threat, so cortisol replacement and stress cover come before thyroid replacement.

In a nutshell

Hypopituitarism causes secondary adrenal, thyroid, gonadal or growth-hormone deficiency. The key safety rule is to replace or cover glucocorticoid deficiency before thyroid hormone. Look for adrenal crisis, apoplexy, visual loss and AVP deficiency, then manage the remaining axes and the underlying pituitary lesion.

Classic presentation

A patient with a pituitary mass or previous postpartum haemorrhage develops fatigue, amenorrhoea or erectile dysfunction and cold intolerance; sudden headache, visual loss or collapse changes this to an emergency.

Key points

  • Secondary endocrine failure gives a low target hormone with an inappropriately low or normal trophic hormone.
  • Adrenal crisis is the immediate life threat; give hydrocortisone without delay.
  • Give glucocorticoid before levothyroxine and monitor secondary hypothyroidism with free T4, not TSH.
  • A mildly raised prolactin can be stalk effect; a sudden headache with visual signs suggests apoplexy.
  • Polyuria and polydipsia may indicate coexisting AVP deficiency and need fluid/sodium safety.

First-line investigation

Paired pituitary/target-gland hormones including cortisol, electrolytes and glucose, followed by specialist dynamic testing and pituitary MRI.

Management

Protect cortisol first

  • If adrenal crisis is suspected, give parenteral hydrocortisone immediately, restore volume and continue stress dosing while arranging endocrine review.2,3

Map all pituitary axes

  • Measure paired pituitary/target-gland hormones, cortisol, electrolytes and glucose; arrange dynamic tests and MRI through endocrinology when stable.2,1

Replace hormones in the safe order

  • Provide glucocorticoid cover before levothyroxine, then replace thyroid, sex and selected growth hormones using axis-specific specialist targets.2,1,4

Educate for emergencies

  • Give sick-day rules, emergency steroid-card/injection advice and clear instructions for vomiting, severe illness, surgery and suspected adrenal crisis.2,3

Treat lesion-related emergencies

  • Urgently image and involve pituitary, neurosurgical and ophthalmology teams for apoplexy, visual loss, chiasmal compression or a secreting/compressing lesion.5

Surveil every axis

  • Continue lifelong endocrine and lesion surveillance, including AVP-deficiency safety, bone health and delayed radiation-related deficiencies.1,4

Exam traps

  • A normal TSH does not exclude secondary hypothyroidism.
  • Starting levothyroxine before treating cortisol deficiency may precipitate adrenal crisis.
  • Secondary adrenal insufficiency usually does not cause the hyperkalaemia and hyperpigmentation of primary disease.
  • A modest prolactin rise may reflect stalk compression rather than a prolactinoma.
  • Pituitary apoplexy needs emergency steroids even before the complete endocrine work-up is available.

Illustrations

Pituitary MRI showing a sellar massA sagittal or coronal MRI of the pituitary showing a sellar or suprasellar mass that may compress the gland or optic chiasm.Philippe Chanson and Sylvie Salenave, Wikimedia Commons · CC-BY-2.0

Key sources

  1. Pituitary Foundation: Hypopituitarism (Current UK patient and professional-facing information on pituitary-axis symptoms, causes and hormone replacement; accessed 4 August 2026.)
  2. NICE NG243: Adrenal insufficiency: identification and management (Current NICE recommendations for secondary and tertiary adrenal insufficiency, hydrocortisone replacement, emergency management and sick-day/emergency-card safety; accessed 4 August 2026.)
  3. Society for Endocrinology: adrenal crisis information and emergency management (UK emergency guidance on immediate hydrocortisone, saline, continuation dosing and prevention of adrenal crisis; current page accessed 4 August 2026.)
  4. British National Formulary (BNF) (Current UK prescribing information for hydrocortisone, levothyroxine, sex hormones, somatropin and desmopressin; product-specific dose, interactions, contraindications and monitoring must be checked at the point of care; accessed 4 August 2026.)
  5. Society for Endocrinology: UK guidelines for the management of pituitary apoplexy (UK pituitary-apoplexy guidance covering emergency hydrocortisone, urgent imaging, visual/neurological assessment and specialist MDT care; published 2011 and accessed 4 August 2026.)Updated 1 Jan 2014

This page is exam revision material, not medical advice, and must not be used for patient care. Always check drug doses against the BNF and current guidance. Full disclaimer.