70. When the pressure stays high, go looking with a closer eye - Resistant Hypertension

Resistant hypertension, defined as uncontrolled blood pressure despite the use of three or more antihypertensive agents at maximum tolerated doses, requires a systematic diagnostic approach to identify potential secondary causes. Clinicians must first rule out pseudoresistance—such as medication nonadherence, white coat effect, or improper measurement—before investigating renal, endocrine, vascular, or drug-induced etiologies. Key secondary drivers include renal artery stenosis, primary hyperaldosteronism, and obstructive sleep apnea, the latter of which is present in approximately 70% of resistant cases. Management strategies involve optimizing pharmacotherapy, such as the addition of spironolactone, alongside targeted interventions like CPAP therapy for sleep apnea or surgical resection for specific adrenal or vascular pathologies. Addressing these underlying mechanisms is essential for preventing long-term end-organ damage to the kidneys, heart, and brain.