Background: Hypertension is recorded as a main cause of disability and death in the world. Excessive sodium ingestion is associated with elevated BP and can attribute to poor BP control despite the use of antihypertensive medications. The aim of our study was to correlate between fractional sodium excretion (as marker to daily sodium consumption) and resistant HTN. Methods: The current study is a single center prospective study conducted on 50 Patients complaining of 1ry type of hypertension at outpatient, inpatient cardiology ward and cardiac care unit in Nasser institute Hospital and according to control of BP, patients were divided into two groups; I: pts with controlled hypertension and Group II: pts with uncontrolled (resistant) hypertension. Results: There was significant higher office systolic and diastolic BP in group II (p < 0.05). Also mean 24hr systolic and diastolic BP was higher in group II. Regarding dipping criteria; there was higher percentage of patients of group II that had non-dipping and reverse dipping BP compared to group I (p=0.020). There was no significant differences as regard
FENa+ results between the 2 groups (P=0.093), while 24h urinary sodium excretion came out with significant higher value in group II (P=0.043) and the amount of 24-hr urinary sodium shows significant correlation regarding hypertension treatment resistance (P = 0.045). Conclusion: 24hUrine sodium, and so "increased dietary sodium amount", could be considered predictor for resistance to antihypertensive TTT, as we found that 24-h Na+ kidney excretion was highly associated with both mean24-h AMBP and office BP elevation.