The adrenal glands are small but their influence reaches every system in the body. Perched above each kidney, these two glands produce hormones that regulate blood pressure, the stress response, fluid balance, metabolism, and the immune system. When the adrenal glands produce too much or too little of these hormones — or when a tumour develops within them — the clinical consequences can be wide-ranging and, without diagnosis, easy to mistake for other conditions.
Each adrenal gland has two distinct parts — the cortex (outer layer) and the medulla (inner core) — which produce entirely different hormones with entirely different functions.
The adrenal cortex produces:
The adrenal medulla produces:
Adrenal disorders are classified by whether they involve hormone excess, hormone deficiency, or structural abnormality. The specific syndrome depends on which hormone is affected.
Hormone effect: Deficiency of cortisol and aldosterone — the body cannot mount an adequate stress response and cannot regulate sodium and fluid balance normally.
Key symptoms: Profound fatigue, weight loss, poor appetite, nausea, low blood pressure, dizziness on standing (orthostatic hypotension), salt craving, muscle weakness, depression, and darkening of the skin (hyperpigmentation) — particularly in skin creases, scars, gums, and pressure areas.
Primary treatment: Lifelong hormone replacement with hydrocortisone (cortisol replacement) and fludrocortisone (aldosterone replacement). Dose adjustment during illness, surgery, or physical stress is essential. Emergency hydrocortisone injection for adrenal crisis.
Hormone effect: Excess cortisol affects virtually every organ system, causing progressive metabolic, cardiovascular, and musculoskeletal damage.
Key symptoms: Central obesity with thin arms and legs, a round 'moon face', fat deposit at the base of the neck ('buffalo hump'), purple stretch marks (striae), easy bruising, thin fragile skin, muscle weakness (particularly proximal — difficulty rising from a chair), hypertension, diabetes, osteoporosis, poor wound healing, mood changes, and menstrual irregularity in women.
Primary treatment: Depends on the cause: surgical removal of a cortisol-secreting adrenal tumour (adrenal Cushing's); surgery or radiotherapy for a pituitary tumour secreting ACTH (Cushing's disease); or reduction of exogenous steroid medication where iatrogenic. Medical therapy (ketoconazole, metyrapone) used while awaiting or between definitive treatments.
Hormone effect: Aldosterone excess — leads to sodium retention, potassium loss, and hypertension. The most common surgically correctable cause of hypertension.
Key symptoms: Hypertension — often difficult to control with standard medications. Hypokalaemia (low potassium) causing muscle cramps, weakness, and fatigue. May be entirely asymptomatic — the diagnosis is made biochemically when hypertension investigation reveals a high aldosterone-to-renin ratio.
Primary treatment: Adrenalectomy (laparoscopic removal of the affected adrenal gland) for a unilateral adenoma — curative for aldosterone excess and often improves blood pressure control. Mineralocorticoid antagonist medication (spironolactone, eplerenone) for bilateral hyperplasia or patients unsuitable for surgery.
Hormone effect: Variable — most are non-functioning benign adenomas. Some secrete cortisol (subclinical Cushing's), aldosterone, or catecholamines silently without classic symptoms.
Key symptoms: Most have no symptoms — the finding is entirely incidental. A subset cause mild autonomous cortisol secretion detected only biochemically (subclinical hypercortisolism), associated with increased metabolic and cardiovascular risk. Functioning tumours may cause hypertension or other hormone-related features.
Primary treatment: All adrenal incidentalomas require biochemical screening for hormone excess (overnight dexamethasone suppression test, plasma metanephrines, aldosterone-to-renin ratio). Imaging characteristics (CT density, size, washout on delayed imaging) determine malignancy risk. Surgical removal for functioning tumours regardless of size, tumours >4 cm, or those with imaging features of malignancy. Surveillance with repeat imaging and biochemistry for small, non-functioning, low-risk tumours.
Adrenal disorders require a structured diagnostic pathway combining biochemical testing (to identify hormone excess or deficiency), imaging (to identify the structural abnormality), and in some cases, sampling procedures (to lateralise disease to one side). The pathway depends on which disorder is suspected.
Treatment is condition-specific and depends on whether the disorder involves hormone excess, deficiency, or a structural lesion. The full range of medical and surgical options is available at Farrer Park Hospital.
Hormone Replacement Therapy: The mainstay of treatment for adrenal insufficiency. Hydrocortisone replaces cortisol (typically in two to three divided daily doses mimicking the natural diurnal rhythm). Fludrocortisone replaces aldosterone in primary adrenal insufficiency. Dosing must be adjusted upward during illness, surgery, or significant physical stress — the 'sick day rule' is critical education for all patients.
Medical Cortisol Suppression: For Cushing's syndrome where surgery is not immediately possible or has been unsuccessful: ketoconazole, metyrapone, or osilodrostat reduce adrenal cortisol production. Pasireotide or cabergoline may be used for Cushing's disease (pituitary-driven). Mitotane for adrenal carcinoma.
Antihypertensive Medications: Mineralocorticoid antagonists — spironolactone or eplerenone — are the first-line medical treatment for bilateral primary hyperaldosteronism. They block the effect of excess aldosterone, controlling blood pressure and normalising potassium. Alpha-blockers and beta-blockers used for phaeochromocytoma management pre-operatively and in non-surgical candidates.
Laparoscopic Adrenalectomy: Minimally invasive removal of the adrenal gland through small keyhole incisions. The preferred approach for most adrenal tumours including functioning adenomas (Cushing's, Conn's), phaeochromocytoma, and adrenal incidentalomas with concerning features. Associated with shorter hospital stay, less blood loss, and faster recovery than open adrenalectomy.
Surveillance: Small, non-functioning adrenal incidentalomas with benign imaging characteristics are managed with periodic surveillance — typically repeat CT at 6–12 months, then annually for 1–2 years. Biochemical retesting annually for 4 years to detect delayed development of hormone secretion.
Adrenal gland disorders can happen to anyone due to Imbalances in the production of these hormones. It can lead to complications such as high blood pressure and diabetes. Adrenal gland disorders also occur due to adrenal fatigue, hormonal imbalances or the presence of tumours.
See a specialist if you have:
Adrenal disorders are rare enough that they are frequently not the first diagnosis a doctor considers — but common enough that delays in diagnosis are clinically significant.
Undiagnosed Cushing's syndrome causes progressive cardiovascular damage, bone loss, and metabolic disease. Undiagnosed phaeochromocytoma carries a risk of hypertensive crisis. Untreated adrenal insufficiency can become life-threatening during periods of physical stress.
Effective treatments exist for all common adrenal disorders. The earlier the diagnosis, the better the outcome.
