General Medicine
Adrenal and Pituitary Disorders
Adrenal and pituitary disorders for MBBS: Cushing syndrome, Addison disease, phaeochromocytoma, primary aldosteronism and pituitary tumours.
MedNext Academy | 3 min read
Adrenal and Pituitary Disorders
Adrenal and pituitary disorders for MBBS: Cushing syndrome, Addison disease, phaeochromocytoma, primary aldosteronism and pituitary tumours.
This supplementary chapter covers disorders of the adrenal glands and pituitary, from cortisol excess and deficiency to primary aldosteronism and phaeochromocytoma. It also addresses pituitary tumours, their mass effects and hormonal syndromes, and the principles of hormone replacement.
High-yield: Adrenal and Pituitary Disorders
- The adrenal cortex produces cortisol, aldosterone and androgens, while the medulla produces catecholamines.
- Cushing syndrome is a state of cortisol excess, most commonly caused by exogenous corticosteroid use.
- Cushing disease specifically refers to cortisol excess driven by a pituitary corticotroph adenoma.
- Features of cortisol excess include central obesity, moon face, striae, hypertension and glucose intolerance.
- The overnight dexamethasone suppression test screens for cortisol excess.
- Addison disease is primary adrenal insufficiency with low cortisol and low aldosterone and skin hyperpigmentation.
- An adrenal crisis presents with hypotension and shock and is treated with intravenous hydrocortisone and fluids.
- Primary aldosteronism causes hypertension with hypokalaemia and a raised aldosterone to renin ratio.
- Phaeochromocytoma causes episodic headache, palpitations and sweating with paroxysmal hypertension.
- Alpha blockade precedes beta blockade in phaeochromocytoma to avoid an unopposed hypertensive crisis.
- A pituitary adenoma can cause a mass effect with bitemporal hemianopia by compressing the optic chiasm.
- Prolactinoma is the commonest functioning pituitary tumour and is treated medically with dopamine agonists.
- Acromegaly results from growth hormone excess, usually from a pituitary adenoma.
- Diabetes insipidus causes polyuria and polydipsia from deficient or ineffective antidiuretic hormone.
- Hypopituitarism requires replacement of the deficient hormones, with cortisol replaced before thyroxine.
Adrenal and pituitary essentials
- **Cortisol excess:** Cushing syndrome; overnight dexamethasone suppression test screens for it.
- **Adrenal insufficiency:** Addison disease with low cortisol and aldosterone; crisis needs hydrocortisone and fluids.
- **Phaeochromocytoma:** Paroxysmal hypertension; alpha blockade before beta blockade.
- **Pituitary tumour:** May cause bitemporal hemianopia; prolactinoma is commonest and treated medically.
Frequently Asked Questions
What is the difference between Cushing syndrome and Cushing disease?
Cushing syndrome is any state of cortisol excess, most often from exogenous steroids, whereas Cushing disease specifically refers to cortisol excess caused by a pituitary corticotroph adenoma.
Why is alpha blockade given before beta blockade in phaeochromocytoma?
Starting a beta blocker first leaves alpha-mediated vasoconstriction unopposed and can precipitate a hypertensive crisis, so alpha blockade is established first.
How does an adrenal crisis present and how is it treated?
An adrenal crisis presents with hypotension and shock, and is treated urgently with intravenous hydrocortisone and fluid resuscitation.
How does this chapter help for NEET-PG?
Cortisol excess and deficiency, phaeochromocytoma management and pituitary tumour effects are common exam themes in endocrinology and general medicine.
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