To evaluate impact the difference in stages ofage and related incidence of hemodialysis patients.Two hundred and fifty patients undergoing hemodialysis were collected from general hospital in Baghdad city /Iraq. The samples with renal failure before hemodialysis were divided into (138) male,( 112)female. The sera were separated from samples to physiological investigation. We found that renal failure was more predominant among the patients ages group ranging from (51-70) years old. The results shows A significant increase in the levels of urea, creatinine, in younger patients (≤ 30 years) when compared with older patients (>70 years). Furthermore a significant decrease in serum levels of total protein in patients in older patients (>70 years) compared with younger group (≤ 30 years). While there are no significant differences in sera levels of albumin among aging group.While this study revealed a significant increase in the level of cholesterol when compared the aging group (>70 years) patients with younger group (≤ 30 years). This study also revealed significant increase in the level of fasting blood glucose (FBS) in the aging group (51-70)year when compared with aging group (31-50) year only. In additionleptin, CRP,Hb and PCV levels a significant increase in the age group (>70) years when compared with (≤ 30 years) group.