This blinded cross-over clinical trial will enroll participants with mild stage 1 hypertension to evaluate whether urinary extracellular transcript abundance predicts response to an mineralocorticoid receptor (MR) antagonist, eplerenone. Eligible participants will have a 2 week wash-in period followed by 4 weeks of treatment with placebo or eplerenone. There will be a 2 week wash out period from study medications and then participants will take the other drug (placebo or eplerenone) for 4 weeks. In addition, participants will also provide urine and blood samples during the trial, have physical assessments, and be monitored for safety.