Background & Objectives: Hypertension is one of the major factors of cardiovascular diseases among hemodialysis patients which shoes its effect along with vascular changes. 75-80% of the patients with ESRD are hypertensive. Despite many available druge to decrease the blood pressure, many of these patients remain hypertensive. The major cause Of Hypertension is the increase in the blood volume which is due to the water and salt retention in the body. It doesn't seem that the uptake of body's fluid for a short period can have a remarkable effect on the pressure.

  Methods: This descriptive analytic study was done on 80 hemodialysis patients who were under trearment at Buali hospital. First patients were investigated according to age, sex, frequency of dialysis in the week and dialysis duration. These for each patient the blood pressure before and during dialysis and weight changes before and after dialysis with two consectiue sessions were measured. Calculated and MAP was determined. Finally data was analyzed through SPSS.

  Results: 48 out of 74 patients (64.9%) had hypertension. Blood pressure was controlled in 41 patients (55.4%). Age, sex, dialysis period and sessions of dialysis did not have a significant relationship with hypertension control. The study showed a high prevalence of high blood pressure in hemodialysis patients (64.9%). The blood pressure was not controlled in the majority of patients (44.6%).

  Conclusion: Patients' weight changes have no significant effect on hypertension. This shows that the causes for blood pressure can be due to other causes different from increase in the blood volume among hemodialysis patients and perhaps the chronic blood volume increase is not related to hypertension.