Once your blood pressure medications are discontinued, you will be closely monitored. If you do not own a home blood pressure monitor, we will provide one for you to use during the study so that you can keep a daily record of your blood pressure readings. We will ask you to call us every three days to report your blood pressure readings. After you have stopped taking your medication, dietitians at the hospital will make you low salt meals to eat at home for about seven days. On the last day of the low salt diet, you will be asked to begin a 24-hour urine collection that you will bring with you when you are admitted to the hospital that evening. That morning, you will be required to come to the Center for Clinical Investigations (CCI) at Brigham and Women's Hospital for a one-hour test to check if your body is in the correct salt balance.