Adrenal Crisis

• Loss of glucocorticoid-mediated cardiovascular homeostasis: Cortisol exerts permissive effects on catecholamine sensitivity through upregulation of α and β adrenergic receptors on vascular endothelium and myocardium, and maintains vascular tone through direct effects on the endothelium. Acute cortisol deficiency causes profound loss of responsiveness to endogenous and exogenous catecholamines, resulting in peripheral vasodilation, decreased peripheral vascular resistance, and inability to maintain blood pressure despite elevated catecholamine levels. The loss of glucocorticoid-mediated maintenance of myocardial contractility further compromises cardiac output. This explains the characteristic finding of hypotension refractory to catecholamine therapy until glucocorticoids are administered—a pathognomonic feature of adrenal crisis.

• Mineralocorticoid deficiency and electrolyte derangement: Aldosterone normally acts at the principal cells of the collecting duct to promote sodium reabsorption and potassium excretion through epithelial sodium channels (ENaC) and Na+/K+ ATPase. Acute loss of aldosterone (particularly in primary adrenal insufficiency) causes sodium wasting, volume depletion, and life-threatening hyperkalemia. The hyperkalemia directly impairs cardiac electrical conduction, causing peaked T waves, prolonged PR intervals, and widened QRS complexes; severe hyperkalemia can precipitate ventricular fibrillation. Hyponatremia develops from combined salt wasting and impaired free water excretion due to loss of cortisol's inhibitory effects on ADH secretion.

• Metabolic derangement and cellular dysfunction: Cortisol is essential for maintaining hepatic gluconeogenesis and suppressing peripheral glucose utilization; acute deficiency causes severe hypoglycemia from both decreased glucose production and increased peripheral utilization. Hypoglycemia impairs cerebral function and reduces catecholamine responsiveness. Loss of cortisol's permissive effect on lipolysis prevents mobilization of free fatty acids needed for energy metabolism. The resulting metabolic acidosis from tissue hypoperfusion and lactate accumulation further impairs myocardial contractility and systemic vascular resistance.

• Loss of proinflammatory and immune regulation: Cortisol normally provides negative feedback inhibition on IL-1, IL-6, TNF-α, and other proinflammatory cytokines; acute deficiency permits unopposed inflammatory cytokine release. This contributes to further vasodilation, increased capillary permeability, and progression to septic shock-like physiology even in the absence of infection. Additionally, the immunosuppressive effects of glucocorticoids are lost, potentially unmasking opportunistic infections (particularly relevant in secondary adrenal insufficiency due to tuberculosis or fungal disease).

• Central nervous system effects: Severe hyponatremia (typically <120 mEq/L in crisis) causes cerebral edema and altered mental status; hypoglycemia exacerbates altered consciousness. The combination produces confusion, lethargy, and ultimately coma if untreated. Fever may paradoxically worsen despite the loss of anti-inflammatory hormone, reflecting uncontrolled cytokine-mediated inflammation.

• Distinguishing primary vs. secondary adrenal insufficiency in crisis: In primary adrenal insufficiency (Addison's disease), both cortisol and aldosterone are deficient, making electrolyte abnormalities (hyperkalemia, hyponatremia) prominent; ACTH levels are markedly elevated. In secondary adrenal insufficiency (pituitary/hypothalamic disease), aldosterone production is often preserved (maintained by the renin-angiotensin system), making hyperkalemia absent and sodium wasting less severe; ACTH is low or inappropriately normal. However, both forms can precipitate life-threatening hypotension and shock if cortisol deficiency is severe enough.

• Autoimmune adrenalitis (Addison's disease): Accounts for ~70% of primary adrenal insufficiency in iodine-sufficient regions; T-cell mediated destruction of adrenocortical cells targeting 21-hydroxylase (most common) and other steroidogenic enzymes. Often presents with insidious onset over months to years, but can decompensate acutely with concurrent illness, surgery, or infection. Associated with other autoimmune conditions (thyroiditis, celiac disease, type 1 diabetes, pernicious anemia—POLYGLANDULAR AUTOIMMUNE SYNDROMES).

• Adrenal tuberculosis: Most common cause of primary adrenal insufficiency worldwide; tuberculosis causes granulomatous infiltration and caseating necrosis of both adrenal glands, typically sparing adrenal cortex initially but progressing to >90% destruction needed for clinical insufficiency. Risk factors include HIV/AIDS (incidence of TB-related adrenal insufficiency ~10% in advanced AIDS), endemic TB regions, immunosuppression, or reactivation tuberculosis.

• Bilateral adrenal hemorrhage/infarction: Acute surgical or spontaneous bleeding into adrenals (often bilateral) causes rapid loss of adrenocortical function, presenting as fulminant adrenal crisis. Etiologies include meningococcal sepsis (Waterhouse-Friderichsen syndrome—the classic association), other gram-negative sepsis, anticoagulation overdose, trauma, antiphospholipid syndrome, adrenal vein thrombosis, or spontaneous hemorrhage in anticoagulated patients. Characterized by rapid progression from fever/sepsis to shock, with computed tomography (CT) showing bilateral adrenal enlargement with hypodensity consistent with hemorrhage.

• Fungal infections: Histoplasmosis, coccidioidomycosis, blastomycosis, and cryptococcosis cause granulomatous adrenal destruction; particularly important in immunocompromised hosts, endemic areas, or disseminated disease. Candida can cause adrenal abscess in critically ill or severely immunocompromised patients.

• Malignancy and metastatic disease: Adrenal lymphoma (particularly in HIV+ patients), metastatic lung cancer, breast cancer, or melanoma to adrenal glands; bilateral involvement is required for clinical insufficiency, occurring in <5% of patients with adrenal metastases.

• Medications: Mitotane (adrenolytic agent used in adrenocortical carcinoma); etomidate (causes dose-dependent adrenal suppression through inhibition of 11β-hydroxylase); ketoconazole (inhibits multiple P450 enzymes including steroid synthesis); rifampin (accelerates glucocorticoid and mineralocorticoid metabolism—important in patients on replacement therapy); phenytoin.

• Other primary causes: Adrenal leukodystrophy (X-linked disorder causing adrenal infiltration with very long chain fatty acids, presenting in childhood but occasionally in adulthood), sarcoidosis (granulomatous infiltration), amyloidosis, hemochromatosis, CMV infection (particularly in AIDS), adrenoleukodystrophy.

• Pituitary adenomas or pituitary surgery/radiation: Craniopharyngiomas, prolactinomas, or non-functioning adenomas causing mass effects and ACTH suppression; transsphenoidal surgery for pituitary pathology commonly causes temporary or permanent ACTH/cortisol deficiency. Radiation to sella turcica (for pituitary or brain tumors) causes delayed ACTH insufficiency in 30-50% of patients within 5-10 years.

• Abrupt glucocorticoid withdrawal: Most common cause of secondary adrenal insufficiency in clinical practice. Prolonged suppressive glucocorticoid therapy (even moderate doses for >2-3 weeks) suppresses hypothalamic CRH and pituitary ACTH through negative feedback, causing adrenal atrophy. Abrupt cessation precipitates crisis, particularly with stress/illness, as the HPA axis requires weeks to months to recover. Steroid withdrawal is frequently tested on boards—patients on >10 mg prednisone daily for >2 weeks should be tapered slowly.

• Hypopituitarism from any cause: Traumatic brain injury, subarachnoid hemorrhage, intracranial surgery, infiltrative disease (lymphocytic hypophysitis, sarcoidosis, tuberculosis, syphilis), apoplexy (sudden hemorrhage into pituitary, presenting with thunderclap headache + vision changes + adrenal crisis).

• Infiltrative/inflammatory disorders: Lymphocytic hypophysitis (autoimmune inflammation of pituitary, increasingly recognized), tuberculosis, syphilis, sarcoidosis.

Precipitating Factors for Crisis in Known/Unknown Adrenal Insufficiency

• Acute medical illness: Infection (pneumonia, gastroenteritis, UTI, meningitis, sepsis), myocardial infarction, stroke, acute coronary syndrome. Stress-induced cortisol requirements increase 5-10 fold during acute illness; inadequate endogenous or exogenous cortisol causes decompensation.

• Surgery and anesthesia: Surgical stress increases cortisol requirements 2-5 fold intraoperatively and postoperatively; inadequate perioperative glucocorticoid coverage (or omission of glucocorticoids in undiagnosed adrenal insufficiency) precipitates crisis in perioperative period.

• Trauma: Accidental injury, motor vehicle accident, or burn causing physiologic stress and increased cortisol demands.

• Medications: Mitotane, etomidate (single-dose suppression of cortisol synthesis—critical in intubated ICU patients), ketoconazole, RIF, phenytoin.

• Pregnancy: Increased cortisol requirements necessitate adjustment of replacement therapy; peripartum complications can precipitate crisis.

Classic Presentation of Acute Primary Adrenal Insufficiency (Waterhouse-Friderichsen Syndrome)

• Fever with fulminant septic shock: Often indistinguishable from meningococcal sepsis; high fever (often 38.5-40.5°C), chills, rigors, and rapid progression to shock over hours. Petechial or purpuric rash may be present (reflecting adrenal hemorrhage from meningococcemia), deepening the confusion with meningococcal disease itself.
• Profound hypotension refractory to catecholamines: Blood pressure typically 70-90/40-60 mmHg or lower; critically, this hypotension does not respond to aggressive fluid resuscitation and vasopressor therapy until glucocorticoids are administered—this is pathognomonic.
• Abdominal pain and gastrointestinal symptoms: Severe, diffuse abdominal pain (from mesenteric ischemia, inflammation, or adrenal hemorrhage), nausea, vomiting, diarrhea, abdominal distention. Abdominal pain may mimic acute surgical abdomen.
• Altered mental status: Confusion, agitation, lethargy, or coma from combined hypoglycemia, hyponatremia, and hypotension-induced cerebral hypoperfusion. May progress from alert to unresponsive within hours.
• Tachycardia and tachypnea: Compensatory responses to shock and metabolic acidosis; respiratory rate may be 25-40 breaths/min.
• Cool, clammy extremities: Peripheral vasoconstriction from shock state despite warm skin centrally (warm shock vs. cold shock distinction not reliable in adrenal crisis).

Presentation of Secondary Adrenal Insufficiency or Chronic Illness Precipitation

• Insidious prodrome over days to weeks: Malaise, weakness, anorexia, weight loss, abdominal pain; often attributed to viral illness or other conditions, delaying recognition.
• Delirium or personality change: Progressive confusion, irritability, or withdrawal.
• Hypotension without prominent fever: Blood pressure in 90-110/50-70 range; may initially be attributed to sepsis, dehydration, or cardiogenic causes.
• Hypoglycemia-related symptoms: Tremor, palpitations, anxiety, sweating, visual disturbance, progressing to seizures or coma if untreated.
• Hyponatremia-related symptoms: Headache, nausea, confusion, seizures; often overlooked as primary process rather than symptom of adrenal insufficiency.

Physical Examination Findings

• Hypotension: Systolic BP <90 mmHg; orthostatic drop of >20 mmHg if patient can be assessed upright.
• Tachycardia: Heart rate typically 100-120+ bpm; may be disproportionately elevated relative to degree of hypotension.
• Altered mental status: Confusion, disorientation, or decreased level of consciousness; Glasgow Coma Scale may be <15.
• Skin findings: Hyperpigmentation of buccal mucosa, areolas, skin creases, or scars (seen in chronic primary adrenal insufficiency, caused by elevated ACTH stimulating melanocytes—may be absent in acute presentation); petechiae or purpura (if underlying meningococcal sepsis); pale, clammy, or mottled skin from shock.
• Abdominal examination: Distention, tenderness, diminished bowel sounds; may mimic acute abdomen.
• Neurologic examination: Focal deficits uncommon unless concurrent CNS pathology; generalized obtundation or seizures from hyponatremia/hypoglycemia.

Important Clinical Variants

• Adrenal crisis masquerading as septic shock: Most common diagnostic challenge; sepsis and adrenal insufficiency may coexist. Clue to adrenal insufficiency is refractory hypotension unresponsive to aggressive fluid and vasopressor therapy—start empiric glucocorticoids if hypotension persists despite >30 mL/kg crystalloid and vasopressors, or if clinical suspicion exists.
• Perioperative adrenal crisis: Occurs in immediate postoperative period (first 24-48 hours post-op) with unexplained hypotension, tachycardia, and altered mental status; may be mistakenly attributed to pain, medication effects, or routine postoperative complications.
• Adrenal crisis from steroid withdrawal: Occurs days to weeks after abrupt cessation of glucocorticoids; patient may report recent tapering of prednisone or corticosteroid inhaler, or history of high-dose steroids for polymyalgia rheumatica, vasculitis, or other inflammatory condition.
• Painless presentation with predominantly neuropsychiatric symptoms: Rare variant with minimal hemodynamic abnormality but prominent delirium, personality change, or psychosis—easily missed as primary psychiatric illness.

Clinical Suspicion and Historical Clues

Immediate stabilisation (treat on suspicion — do not wait for cortisol results)

• Draw, then treat: Obtain a serum cortisol, ACTH, renin/aldosterone, electrolytes, and glucose in the same motion as placing the IV, but give steroid immediately. The Endocrine Society clinical practice guideline on primary adrenal insufficiency is explicit that treatment must never be delayed for diagnostic confirmation.
• Glucocorticoid (drug of choice): Hydrocortisone 100 mg IV bolus, followed by 200 mg over 24 hours by continuous infusion or 50 mg IV every 6 hours (Endocrine Society). Hydrocortisone is preferred because at these doses it also saturates the mineralocorticoid receptor, restoring catecholamine responsiveness and renal sodium retention simultaneously.
• If the diagnosis is genuinely unknown: Dexamethasone 4 mg IV is an acceptable substitute because it is not detected by cortisol immunoassays, preserving the ability to perform a cosyntropin (250 mcg IV) stimulation test afterwards. It has no mineralocorticoid activity and is not a long-term answer.
• Volume and glucose: Rapid isotonic crystalloid (normal saline), typically 1 L in the first hour with further boluses guided by perfusion; add dextrose (D50 IV push, then dextrose-containing maintenance) for hypoglycaemia.
• Vasopressors (norepinephrine) are adjunctive only — pressor unresponsiveness reverses once glucocorticoid is on board.

Concurrent and second-line measures

• Treat the precipitant: empiric antimicrobials for suspected sepsis per Surviving Sepsis Campaign; imaging for adrenal haemorrhage.
• Hyperkalaemia: calcium gluconate for ECG changes, then insulin/dextrose; it usually corrects with hydrocortisone and saline.
• Fludrocortisone: add only when hydrocortisone is tapered below roughly 50 mg/day, once the mineralocorticoid effect of high-dose hydrocortisone is lost.

Complications of the disease (all time-critical)

• Refractory hypovolaemic/vasodilatory shock and death — emergency: loss of the permissive effect of cortisol on adrenergic receptors means escalating pressor requirements with no haemodynamic response; the signal is a rising norepinephrine dose with persistent lactataemia and oliguria that abruptly improves after hydrocortisone.
• Hyperkalaemic cardiac arrest — emergency: aldosterone deficiency abolishes distal K⁺ secretion; watch for peaked T waves, PR prolongation, QRS widening, then a sine-wave pattern preceding ventricular fibrillation. Any ECG change mandates immediate calcium.
• Hypoglycaemic seizure or coma — emergency: failure of hepatic gluconeogenesis; signalled by unexplained obtundation or focal deficits with a low fingerstick glucose.
• Hyponatraemic encephalopathy — emergency: combined salt wasting and loss of cortisol's tonic inhibition of ADH; headache, vomiting, seizures with a markedly low serum sodium.
• Disseminated intravascular coagulation and bilateral adrenal infarction in Waterhouse–Friderichsen syndrome: purpura fulminans with thrombocytopenia and prolonged coagulation times; adrenal destruction is permanent.
• Acute kidney injury and mesenteric hypoperfusion from prolonged shock.

Complications of treatment

• Osmotic demyelination syndrome — emergency and the classic iatrogenic trap: glucocorticoid replacement removes the ADH stimulus, producing a brisk free-water diuresis so that sodium corrects faster than intended. Signalled by a sodium rise exceeding the guideline-endorsed limit over 24 hours, then delayed (days later) dysarthria, quadriparesis, or a locked-in state. Monitor sodium frequently and consider desmopressin to re-lower the rate if overcorrection occurs.
• Volume overload/pulmonary oedema from aggressive crystalloid in patients with cardiac or renal disease.
• Hyperglycaemia, hypokalaemia, hypertension, and oedema from supraphysiologic steroid and mineralocorticoid effect.
• Steroid psychosis, delirium, and insomnia — distinguish from crisis-related encephalopathy.
• Immunosuppression with reactivation of latent infection (tuberculosis, fungal disease) during prolonged high-dose therapy.

• Single best next step: give IV hydrocortisone — never "obtain a cosyntropin stimulation test" or "await the a.m. cortisol." Drawing labs and treating happen together; only the treatment is time-critical.
• The pathognomonic stem phrase: hypotension refractory to fluids and vasopressors that reverses within hours of steroid. If a stem gives escalating pressors with no response, think adrenal crisis before cardiogenic shock.
• The classic lab quartet: hyponatraemia + hyperkalaemia + hypoglycaemia + eosinophilia (with a relative lymphocytosis). Eosinophilia in a hypotensive patient is a favourite giveaway.
• Dexamethasone is the assay-friendly steroid: if the diagnosis is undeclared and you want a valid cosyntropin (250 mcg IV) test later, dexamethasone does not cross-react with cortisol immunoassays. Hydrocortisone does. Dexamethasone is a bridge, not the long-term regimen — it has no mineralocorticoid activity.
• The association examiners test: Waterhouse–Friderichsen syndrome — meningococcaemia, purpura, bilateral adrenal haemorrhage. Also know etomidate (11β-hydroxylase inhibition) precipitating crisis in an intubated ICU patient, and abrupt glucocorticoid withdrawal as the commonest cause overall.
• Primary versus secondary: hyperpigmentation and hyperkalaemia belong to primary disease (high ACTH, absent aldosterone). Their absence, plus other pituitary hormone deficits, points to secondary — where the renin–angiotensin axis keeps aldosterone intact.
• Common distractor: adding fludrocortisone during the acute phase. At stress-dose hydrocortisone the mineralocorticoid receptor is already occupied; fludrocortisone becomes relevant only as the hydrocortisone dose is tapered.
• Second common distractor: attributing the presentation to an acute abdomen. Diffuse abdominal pain with guarding in a hypotensive, hyponatraemic patient is crisis until proven otherwise — laparotomy will kill them.