Background: Both chronic kidney disease (CKD) and acute kidney injury (AKI) represent major contributors to global morbidity, often progressing to advanced renal dysfunction requiring hemodialysis (HD). While the clinical characteristics of these conditions are individually well described, direct comparisons of their etiological, clinical, and hematological profiles among patients receiving HD remain limited. This study aimed to evaluate and contrast these parameters in patients with CKD and AKI undergoing HD. Materials and Methods: This prospective, observational, cross-sectional study was conducted at Sree Mookambika Institute of Medical Sciences, Tamil Nadu, India, over an 18-month period from January 2023 to June 2024. A total of 425 adult patients undergoing hemodialysis were enrolled, including 328 patients with CKD and 97 patients with AKI. Data regarding demographic characteristics, clinical features, etiological factors, and laboratory parameters, including hematological investigations, were systematically collected and analyzed. Results: Hypertension emerged as the leading underlying cause among patients with CKD (75.9%), whereas sepsis was the most common precipitating factor in AKI (49.48%). Patients with CKD were significantly older and had a higher body mass index compared to those with AKI (p=0.005 and p<0.0001, respectively). Gastrointestinal symptoms, breathlessness, anorexia, and jaundice were observed more frequently in the AKI group, while cognitive impairment and peripheral edema were more prevalent among CKD patients. Biochemical evaluation revealed a significantly higher occurrence of hyperkalemia and severe proteinuria in AKI patients, whereas moderate proteinuria and moderate anemia were more commonly associated with CKD. Conclusion: Distinct differences exist in the etiological, clinical, and hematological profiles of patients with CKD and AKI undergoing hemodialysis. Hypertension and sepsis remain the dominant contributors to CKD and AKI, respectively. Advanced age and elevated BMI are more strongly linked to CKD, while AKI is characterized by pronounced metabolic disturbances. Recognition of these differences may aid in early diagnosis and targeted management strategies.

Acute kidney injury, Chronic kidney disease, Hemodialysis, Hypertension, Sepsis