Renovascular hypertension should be suspected if Diastolic hypertension develops abruptly in a patient < 30 or > 50 New or previously stable hypertension rapidly worsens over a period of 6 months Hypertension is initially very severe (systolic > 180 mm Hg) There is unexplained worsening renal function Hypertension is resistant to drug treatment A history of trauma to the back or flank or acute pain in this region with or without hematuria suggests renovascular hypertension (possibly due to arterial injury), but these findings are rare.