Hyperaldosteronism

Hyperaldosteronism is a disorder characterized by excess production of the mineralocorticoid hormone aldosterone, leading to sodium retention, potassium loss, and metabolic alkalosis. It is a common cause of secondary hypertension and can result in resistant high blood pressure if not identified and treated.

There are two main forms: primary and secondary hyperaldosteronism. Primary hyperaldosteronism (also known as Conn's syndrome) results from autonomous aldosterone production by the adrenal cortex, most often due to an aldosterone-producing adenoma or bilateral adrenal hyperplasia. Secondary hyperaldosteronism occurs when increased renin release drives aldosterone synthesis in conditions that reduce effective arterial blood volume or renal perfusion, such as renovascular disease, heart failure, cirrhosis, nephrotic syndrome, or certain medications.

Clinical features vary and include hypertension, often resistant to treatment, and hypokalemia which can cause muscle weakness, cramps, fatigue, and paresthesias. Some patients may be asymptomatic and diagnosed through routine testing or during evaluation for hypertension.

Diagnosis typically begins with screening for hyperaldosteronism using the aldosterone-to-renin ratio (ARR). An elevated ARR suggests the condition and is followed by confirmatory tests such as a saline or oral salt loading test or a fludrocortisone suppression test. Imaging with CT or MRI helps identify adrenal abnormalities, and adrenal vein sampling may be used to distinguish unilateral from bilateral disease when surgery is considered.

Treatment depends on the underlying cause. Unilateral aldosterone-producing adenomas are usually treated with surgical adrenalectomy. Bilateral adrenal hyperplasia is managed with mineralocorticoid receptor antagonists, such as spironolactone or eplerenone, and by addressing hypertension and electrolyte abnormalities. Effective management reduces cardiovascular risk and improves potassium balance.