Understanding Resistant Hypertension

Definition and Diagnosis

Resistant hypertension is defined as blood pressure exceeding 130/80 despite treatment with three properly dosed medications (including a diuretic), or controlled blood pressure requiring four or more medications. It affects approximately one in five or six hypertension patients. When evaluating resistant hypertension, clinicians must first differentiate between truly resistant and pseudo-resistant cases. Pseudo-resistance may result from measurement errors, white coat resistance (blood pressure elevated only in clinical settings), or medication non-adherence. A stepwise diagnostic approach begins with confirming true resistance, then identifying interfering substances like anti-inflammatories or stimulants, and finally screening for secondary causes such as primary aldosteronism, thyroid disease, or renal artery stenosis.

With stricter blood pressure goals (130/80), more patients are being classified as resistant. Common contributing factors include obesity, advanced age, chronic kidney disease, diabetes, and other comorbidities that complicate treatment. Proper blood pressure measurement technique is critically important for accurate diagnosis. Out-of-office measurements, including home blood pressure monitoring or ambulatory blood pressure monitoring, can help identify white coat resistance in patients whose blood pressure appears uncontrolled in clinical settings but is actually well-managed elsewhere. After excluding pseudo-resistance and secondary causes, clinicians can focus on appropriate pharmacologic approaches.