What is the most common cause of secondary hypertension?

• A. Endocrine disorders
• B. Renal artery stenosis
• C. Pheochromocytoma
• D. Chronic Kidney Disease

Answer: (D)

Secondary hypertension arises from a specific, identifiable cause. The most common cause is chronic kidney disease. Damaged kidneys struggle to excrete sodium and water, leading to fluid retention and increased blood volume. In addition, CKD chronically activates the renin-angiotensin-aldosterone system and the sympathetic nervous system, increasing vasoconstriction and sodium retention. These combined effects raise blood pressure and often produce resistant hypertension that needs multiple medications. The other options can cause secondary hypertension but are much less common: renal artery stenosis causes HTN by reduced renal perfusion and RAAS activation, pheochromocytoma presents with episodic surges of catecholamines, and various endocrine disorders also contribute but far less frequently than CKD.