Primary unilateral adrenal hyperplasia

Primary unilateral adrenal hyperplasia (PUAH) is a rare cause of primary aldosteronism (also known as Conn syndrome spectrum), in which one adrenal gland becomes enlarged (hyperplastic) and produces excessive amounts of the hormone aldosterone. Unlike bilateral idiopathic adrenal hyperplasia, PUAH involves only one adrenal gland. Aldosterone is a key hormone that regulates sodium and potassium balance and blood pressure. Excess aldosterone leads to hypertension (high blood pressure), hypokalemia (low potassium levels), and metabolic alkalosis. Patients may experience symptoms such as muscle weakness, fatigue, headaches, excessive urination (polyuria), and excessive thirst (polydipsia) related to potassium depletion and high blood pressure. PUAH primarily affects the endocrine and cardiovascular systems. It is distinguished from aldosterone-producing adenomas (APAs) and bilateral adrenal hyperplasia through adrenal venous sampling, which demonstrates lateralized aldosterone secretion from the affected gland, and imaging studies such as CT scanning, which may show unilateral adrenal enlargement without a discrete adenoma. The condition is an important diagnosis to identify because, unlike bilateral idiopathic hyperaldosteronism which is typically managed medically, PUAH can be effectively treated with unilateral adrenalectomy (surgical removal of the affected adrenal gland). Following surgery, many patients experience significant improvement or resolution of hypertension and normalization of potassium levels. For patients who are not surgical candidates, medical management with mineralocorticoid receptor antagonists such as spironolactone or eplerenone can help control blood pressure and correct electrolyte abnormalities.

Common questions about Primary unilateral adrenal hyperplasia