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Causes and Incidence Most cases are caused by an adenoma of the adrenal gland. Other causes are adrenal nodular hyperplasia and adrenal carcinoma. Only 0.5% to 2% of those with hypertension are affected. The condition is three times more likely to affect women; the typical age ranges from 30 to 50 years.

Disease Process Excess production of aldosterone leads to hypernatremia, hypervolemia, and hypokalemic alkalosis. Mild to severe arterial hypertension occurs because of the increased volume and arteriolar sodium levels. Hypokalemia results from increased renal excretion of potassium, and metabolic alkalosis occurs because of an increase in hydrogen ion secretion. Over time this leads to transient paralysis and tetany.

Symptoms In many cases the only manifestation is a mild to moderate hypertension. Other signs and symptoms include episodic weakness, fatigue, paresthesia, polyuria, polydipsia, and nocturia. Glycosuria, hyperglycemia, and personality disturbances are occasionally manifested.

Potential Complications Marked alkalosis with transient paralysis, tetany, and positive Chvostek's and Trousseau's signs.

Diagnostic Tests

Plasma renin activity

Decreased (measured after restricted sodium/diuretic therapy)

Aldosterone levels

Increased (measured after sodium loading)

Blood chemistry

Normal/increased sodium, decreased potassium

Computed tomography scan

To detect presence of adenoma

Blood pressure

Elevated

Edema

Absent

Treatments

Surgery

Adrenalectomy

Drugs

Spironolactone (Aldactone)

General

Low-sodium diet; instruction about medication, diet, and surgery