Hypertension in Hemodialysis

\- Adults with hypertension on hemodialysis Hypertensive, long-term (3 months or more) hemodialysis patients will be studied over a 6 hemodialysis baseline phase during which 44-hour interdialytic ambulatory BP will be performed and baseline symptoms collected. Patients with well-controlled hypertension, on anti-hypertensive therapy will have blood pressure medications withdrawn until they become hypertensive as assessed by 44-hour interdialytic ambulatory blood pressure recording. We will exclude patients who have had vascular event (stroke, myocardial infarction or limb ischemia requiring bypass) within previous six months, ambulatory BP \>170 mm Hg systolic or \>100 mm Hg diastolic, those who miss 2 or more hemodialysis treatments in the previous month, abuse street-drugs, require home oxygen, have symptomatic congestive heart failure or are morbidly obese (body mass index \> 40 kg/m2).