REN and Hypokalemia: Moreover, in an updated approach to the diagnosis of primary aldosteronism, a suppressed renin activity (PRA) of at least less than 1.0 ng/mL/h (ideally plasma renin activity < 0.6 ng/mL/h or plasma renin concentration < 5 mU/L), plasma aldosterone concentration greater than 15 ng/dL and a high pretest probability consisting of resistant hypertension and/or hypokalemia, an “overtly positive screen” is detected and no further dynamic testing is required [5].