What is the most common cause of secondary hypertension?

The most common cause of secondary hypertension is kidney disease. Secondary hypertension is high blood pressure that results from an underlying medical condition, and kidney disease is frequently implicated in this category. This is primarily due to the kidneys' critical role in regulating blood volume and systemic vascular resistance. When kidney function is compromised, it can lead to fluid retention and increased renin production, both of which can elevate blood pressure.

Conditions such as chronic kidney disease, renal artery stenosis, and glomerulonephritis are common contributors to this form of hypertension. Recognizing kidney disease as the leading cause is essential for appropriate diagnosis and management, as treating the underlying kidney issue can help in controlling blood pressure.

Other potential causes of secondary hypertension, such as obstructive sleep apnea, thyroid disorders, and medications, do exist and can contribute to elevated blood pressure, but they are not as prevalent as kidney disease. Each of these conditions has its own set of mechanisms and implications for blood pressure regulation, but kidney issues remain the most frequently encountered in clinical practice. This foundational understanding highlights the importance of screening for renal function when evaluating patients with hypertension.