The adrenal glands are two small, triangular glands that sit on top of each kidney. Despite their small size, they produce hormones that are essential for life — including cortisol, aldosterone, DHEA, and adrenaline (epinephrine). Adrenal disorders arise when these glands produce too much or too little of these critical hormones.

Anatomy and Function

Each adrenal gland has two distinct parts:

  • Adrenal cortex (outer layer): Produces corticosteroids — cortisol (stress response, metabolism), aldosterone (blood pressure/sodium regulation), and DHEA/androgens
  • Adrenal medulla (inner core): Produces catecholamines — epinephrine (adrenaline) and norepinephrine, the "fight or flight" hormones

Cushing's Syndrome — Excess Cortisol

Cushing's syndrome results from prolonged exposure to excess cortisol. The most common cause is exogenous (from taking corticosteroid medications). Endogenous Cushing's may be caused by a pituitary adenoma producing excess ACTH (Cushing's disease), an adrenal tumor, or an ectopic ACTH-secreting tumor.

Symptoms: Central obesity with a "buffalo hump" (fat between shoulders), moon face, purple stretch marks (striae), easy bruising, muscle weakness, hypertension, high blood sugar, osteoporosis, and depression.

Diagnosis: 24-hour urine free cortisol, late-night salivary cortisol, or overnight low-dose dexamethasone suppression test. MRI of the pituitary or CT of the adrenals identifies the source.

Treatment: Surgical resection of the causative tumor. Medical therapies (metyrapone, ketoconazole, osilodrostat) may be used if surgery is not possible or while awaiting surgery.

Adrenal Insufficiency — Too Little Cortisol

Adrenal insufficiency occurs when the adrenal glands cannot produce adequate cortisol. Primary adrenal insufficiency (Addison's disease) involves the adrenal glands themselves — most commonly autoimmune destruction. Secondary adrenal insufficiency results from pituitary ACTH deficiency, most commonly from prolonged steroid use causing adrenal suppression.

Symptoms: Fatigue, weakness, weight loss, low blood pressure, dizziness, nausea, abdominal pain, and hyperpigmentation (primary only — due to elevated ACTH). Can precipitate an adrenal crisis — a life-threatening emergency with extreme hypotension and shock — during illness, surgery, or trauma.

Treatment: Lifelong hydrocortisone replacement (or prednisone). Patients must double or triple their dose during illness, fever, or surgery ("sick day rules") and carry emergency injectable hydrocortisone for crises.

ðŸšĻ Adrenal Crisis: People with adrenal insufficiency who are severely ill, vomiting, or cannot take oral medications need emergency hydrocortisone injection. This is life-threatening — always carry a glucocorticoid emergency injection kit and wear medical alert identification.

Primary Aldosteronism (Conn's Syndrome)

Excess aldosterone from the adrenal gland is a cause of secondary hypertension, accounting for 5–10% of all hypertension cases. It causes high blood pressure that is difficult to control, and often low potassium. Diagnosed by elevated aldosterone-to-renin ratio. Treatment is surgical (if unilateral) or with aldosterone-blocking medications (spironolactone/eplerenone).

Pheochromocytoma

A rare tumor of the adrenal medulla that secretes excess catecholamines (adrenaline), causing episodes of severe hypertension, headache, sweating, and palpitations. Diagnosed by elevated plasma or urine metanephrines. Treatment is surgical. Alpha-blockade before surgery is mandatory to control blood pressure.

Adrenal Incidentaloma

An adrenal mass discovered incidentally on imaging done for another reason. Found in 3–5% of CT scans. Most are benign non-functioning adenomas requiring only monitoring. Evaluation includes hormonal assessment (rule out subclinical Cushing's, pheochromocytoma, aldosteronism) and imaging characterization to assess malignancy risk.

Key Takeaways

  • The adrenal glands produce cortisol, aldosterone, and adrenaline — all essential hormones
  • Cushing's syndrome (excess cortisol) causes central obesity, stretch marks, and metabolic complications
  • Adrenal insufficiency (Addison's) requires lifelong steroid replacement and emergency preparedness
  • Primary aldosteronism is an underdiagnosed cause of difficult-to-control hypertension
  • Adrenal incidentalomas are common and most are benign — but all require hormonal evaluation
Medical Disclaimer: This article is for educational purposes only and does not constitute medical advice. Always consult with a qualified healthcare provider before making any changes to your treatment plan. Individual medical decisions should be made in partnership with your physician based on your specific circumstances.