Adrenal Disorders for Step 1: Addison, Cushing, CAH, Pheo

Creator: Progress Note
Published: 2026-05-19
Keywords: adrenal insufficiency cortisol, adrenal disorders usmle, addison disease hyperpigmentation, primary vs secondary adrenal insufficiency, cushing syndrome dexamethasone test, conn syndrome hyperaldosteronism, pheochromocytoma alpha blocker, congenital adrenal hyperplasia 21 hydroxylase, adrenal crisis, adrenal cortex zones

bolt The 60-second version

check_circleAdrenal cortex zones: glomerulosa (aldosterone), fasciculata (cortisol), reticularis (androgens); the medulla makes catecholamines.
check_circlePrimary adrenal insufficiency (Addison disease): low cortisol and aldosterone with high ACTH → hyperpigmentation, hyponatremia, hyperkalemia, hypotension. Autoimmune is most common in developed countries.
check_circleSecondary insufficiency (low ACTH, often after stopping chronic steroids): no hyperpigmentation and no hyperkalemia, because aldosterone is regulated by renin.
check_circleCushing syndrome: exogenous steroids are the most common cause. Endogenous: pituitary adenoma (Cushing disease), ectopic ACTH (small cell lung cancer), or adrenal tumor.
check_circlePrimary hyperaldosteronism: hypertension, hypokalemia, metabolic alkalosis, low renin; treat with spironolactone or surgery.
check_circle21-Hydroxylase deficiency (most common CAH): low cortisol and aldosterone, excess androgens → salt wasting and virilization; high 17-hydroxyprogesterone.

target What you'll be able to do · aligned to USMLE Step 1 · Endocrine System

ENDOLink each adrenal zone to its hormone and regulator.
ENDODistinguish primary from secondary adrenal insufficiency.
ENDOLocalize the cause of Cushing syndrome with ACTH and dexamethasone tests.
ENDORecognize hyperaldosteronism, pheochromocytoma, and CAH.

How the adrenal gland is tested on Step 1

Match each zone to its hormone and regulator.

Zone	Hormone	Main regulator
Zona glomerulosa	Aldosterone	Angiotensin II, potassium
Zona fasciculata	Cortisol	ACTH
Zona reticularis	Androgens (DHEA)	ACTH
Medulla	Epinephrine, norepinephrine	Sympathetic preganglionic fibers; cortisol induces PNMT

Memory aid "GFR" for the zones, outside in: salt, sugar, sex.

Adrenal insufficiency

ACTH level separates primary from secondary.

Adrenal insufficiency. Confirm with a cosyntropin (ACTH) stimulation test. Waterhouse-Friderichsen syndrome is adrenal hemorrhage in meningococcal sepsis.

Adrenal crisis: shock, vomiting, abdominal pain, hypoglycemia; give IV hydrocortisone and fluids immediately.
Long-term treatment: hydrocortisone plus fludrocortisone in primary disease; increase steroid doses during illness.

Cushing syndrome

Confirm excess cortisol, then find the source.

Cushing syndrome. Features include central obesity, moon face, purple striae, proximal weakness, hypertension, hyperglycemia, and osteoporosis.

Aldosterone, catecholamine, and enzyme disorders

Hypertension with low potassium or spells points here.

Disorder	Findings	Treatment or clue
Primary hyperaldosteronism (Conn)	Hypertension, hypokalemia, metabolic alkalosis, low renin	Adenoma or bilateral hyperplasia; spironolactone or surgery
Secondary hyperaldosteronism	High renin (renal artery stenosis, heart failure, cirrhosis)	Treat the cause
Pheochromocytoma	Episodic headache, sweating, palpitations, hypertension; high metanephrines	α blocker (phenoxybenzamine) before β blocker, then surgery; MEN2, VHL, NF1
21-Hydroxylase deficiency	Salt wasting, hypotension, hyperkalemia; virilization; ↑ 17-OH progesterone	Glucocorticoid and mineralocorticoid replacement
11β-Hydroxylase deficiency	Hypertension (from 11-deoxycorticosterone), low renin, virilization	Glucocorticoids
17α-Hydroxylase deficiency	Hypertension, hypokalemia, no sex hormones	Ambiguous genitalia in XY; no puberty in XX

Neuroblastoma, the most common adrenal medulla tumor in children, raises urine homovanillic and vanillylmandelic acid.

Worked example

Use ACTH and dexamethasone results.

functions Worked example — localizing Cushing syndrome

A patient with central obesity, striae, and high late-night salivary cortisol has an elevated ACTH. A high-dose dexamethasone test suppresses cortisol. Where is the lesion?

High cortisol with high ACTH means an ACTH-dependent cause (pituitary or ectopic).
Pituitary adenoma cells still respond to strong negative feedback.
Suppression with high-dose dexamethasone therefore points to the pituitary.
Ectopic ACTH tumors usually do not suppress.

Answer. Pituitary ACTH-secreting adenoma (Cushing disease); obtain pituitary MRI.

Next in the roadmap

Adrenal Insufficiency

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3 real questions on Adrenal Disorders

Straight from the Progress Note question bank, each with a cited explanation. No account needed.

From our NCLEX bank

A nurse cares for the client with adrenal insufficiency described in the exhibit. What is the nurse's priority action?

From our NCLEX bank

A nurse is caring for a client with adrenal insufficiency who develops severe hypotension, weakness, and nausea after a day of vomiting. Which action by the nurse is the priority?

From our NCLEX bank

A client with adrenal insufficiency is admitted with vomiting and dizziness. Which findings would the nurse expect?

Frequently asked questions

Why is there hyperpigmentation in Addison disease?expand_more

High ACTH is made from POMC, which also yields melanocyte-stimulating hormone.

Why is potassium normal in secondary adrenal insufficiency?expand_more

Aldosterone is controlled mainly by renin-angiotensin, not ACTH.

What is the most common cause of Cushing syndrome?expand_more

Exogenous glucocorticoid use.

Why give an α blocker before a β blocker for pheochromocytoma?expand_more

Blocking β alone leaves α1 vasoconstriction unopposed, worsening hypertension.

References & further reading

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