It is well known that Aldosterone (aldo) can cause hypertension (HBP). Since aldo is known to cause the kidney to retain sodium (Na) and Na retention is known to cause HBP, it has been thought that the mechanism by which aldo causes HBP is by Na retention. Recent studies have suggested that aldo has many effects in addition to its ability to cause the kidney to retain Na. To test the hypothesis that aldo can cause HBP in a manner which does not involve Na retention, we plan, in this protocol, to give Eplerenone, a specific aldo antagonist, to patients on dialysis who have HBP. A positive effect of Eplerenone to lower HBP in these patients would support this hypothesis.