Hypokalemia Masks Primary Aldosteronism: Diagnostic Pitfalls and Rural Challenges

Abstract

 

Objective: Primary aldosteronism (PA) is a common but frequently underdiagnosed cause of secondary hypertension, particularly in low-resource settings where access to hormonal assays and confirmatory testing is limited. Hypokalemia, although traditionally associated with PA, is absent in most cases and may suppress aldosterone levels, further complicating diagnosis. This report describes a patient with recurrent hypokalemia and long-standing resistant hypertension, illustrating the diagnostic challenges encountered in rural clinical environments.

Case Report: A 43-year-old woman with a ten-year history of uncontrolled hypertension presented with fatigue and repeated episodes of severe hypokalemia requiring hospitalization. Despite multiple antihypertensive medications and continuous potassium supplementation, her blood pressure remained markedly elevated at 195/99 mmHg, and serum potassium was 2.2 mmol/L. Electrocardiography and chest radiography were unremarkable. Contrast-enhanced abdominal computed tomography demonstrated a 20 mm enhancing lesion in the left adrenal gland. Endocrine evaluation revealed markedly elevated aldosterone levels (78.40 ng/dL) with normal cortisol concentrations. A diagnosis of primary aldosteronism due to an aldosterone-producing adenoma was established. The patient underwent laparoscopic left adrenalectomy, and histopathological examination confirmed adrenal cortical adenoma. Following surgery, her blood pressure normalized without the need for antihypertensive therapy, and potassium levels remained stable.

Conclusions: This case underscores the importance of recognizing primary aldosteronism in patients with resistant hypertension and recurrent hypokalemia, particularly in settings with limited diagnostic resources. Early identification and timely surgical intervention can prevent prolonged disease, reduce cardiovascular risk, and offer the possibility of complete clinical cure.