Who should be screened for secondary causes of hypertension

The case of a 34-year-old patient with uncontrolled hypertension is described in this article, together with the diagnostic path followed in order to make the diagnosis, that finally reveals an arteriovenous fistula due to an old kidney biopsy. Uncontrolled or resistant hypertension may be caused by unrecognized secondary hypertension: we revise the clinical and laboratory criteria for selecting hypertensive patients in whom to look for secondary hypertension through the most appropriate diagnostic work up. A synthesis of the main causes of secondary hypertension is also provided in the discussion.