Glucocorticoids and Mineralocorticoids

Core Concepts

Cortisol: the glucocorticoid

Cortisol, from the zona fasciculata, is released in a circadian rhythm (highest in early morning) and does three jobs: it promotes gluconeogenesis (making glucose), raising blood glucose and opposing insulin; it supports blood pressure and vascular responsiveness during stress; and it broadly dampens inflammation and immunity — what makes glucocorticoid drugs so useful and so risky.

Synthetic glucocorticoids (the hydrocortisone/prednisone/dexamethasone family) are designed variations on cortisol, differing in potency, duration, and mineralocorticoid activity: hydrocortisone, for example, has meaningful mineralocorticoid activity, while many other glucocorticoids have little or none — a distinction that matters when choosing replacement therapy.

Aldosterone: the mineralocorticoid

Aldosterone, from the zona glomerulosa, is governed by the RAAS: low blood pressure or low sodium triggers renin, which generates angiotensin II, which stimulates aldosterone. Aldosterone then tells the distal nephron to reabsorb sodium (and with it, water) and excrete potassium. The net effect: volume maintenance and blood-pressure support, at the price of potassium loss — explaining the classic findings of aldosterone excess (hypertension, low potassium) and the risks of mineralocorticoid therapy (potassium loss, fluid retention).

Adrenal insufficiency: when replacement is needed

Primary adrenal insufficiency (Addison disease) means the adrenal cortex itself fails, so both cortisol and aldosterone are deficient: hypotension, hyperkalemia, hyponatremia, fatigue, weight loss — and, in primary disease, hyperpigmentation, because the pituitary pours out extra ACTH (whose precursor also stimulates melanocytes). Secondary adrenal insufficiency comes from pituitary or hypothalamic failure: ACTH and cortisol fall while aldosterone, driven by the RAAS rather than ACTH, is usually preserved. Replacement follows the deficit:

• Glucocorticoid replacement (e.g., hydrocortisone class) supplies missing cortisol.
• Mineralocorticoid replacement (fludrocortisone) adds aldosterone-like activity — typically in primary insufficiency.

Two safety concepts shape nursing care. First, "stress dosing" — during illness, injury, or procedures, a person with adrenal insufficiency may need extra glucocorticoid; the amount, timing, and route are prescriber-directed, and nurses verify the plan. Second, never stop abruptly — exogenous glucocorticoids suppress the person's own axis, so discontinuation is always tapered under prescriber direction.

Glucocorticoid excess: Cushing syndrome

Excess cortisol — from a pituitary adenoma (Cushing disease), an adrenal tumor, or prolonged high-dose glucocorticoid therapy — produces Cushing syndrome: central weight gain, rounded "moon" face, thin skin, easy bruising, muscle weakness, hyperglycemia, hypertension, mood changes. Management is cause-directed (often surgical), with medication used adjunctively per guidelines. But the more common "excess" nurses see is therapeutic: long-term glucocorticoid therapy carries the same metabolic toll — hyperglycemia, weight gain, osteoporosis, immunosuppression, HPA suppression — which is why glucose, blood pressure, weight, bone health, and infection risk are monitored routinely.

Primary aldosteronism

Excess aldosterone (usually a benign adrenal adenoma, Conn syndrome) presents as hypertension with hypokalemia — sometimes with muscle weakness or cramps. Treatment is cause-directed or medication-based per guidelines; the nursing contribution is recognizing the pattern and monitoring potassium and blood pressure.

Nursing considerations

• Know the two families: glucocorticoids = metabolism/inflammation/stress; mineralocorticoids = sodium/potassium/volume. A drug's name doesn't tell you which it is — check the class and its activity profile in references.
• Never stop steroids abruptly; follow the taper plan and teach why; during illness, people on replacement therapy may need prescriber-directed stress dosing — they should contact their care team early.
• Monitor the ripple effects: glucose, potassium, sodium, blood pressure, weight, infection; report promptly per orders.
• Person-first, verification-first: treat the person, not the lab value; scope and prescribing authority vary by licensure and institution — verify everything against references, formulary, and orders.

Common Confusions