Hemodialysis is a medical methodology and a significant domain of clinical and bioengineering research focused on the extracorporeal purification of blood. This process involves using a semipermeable membrane within a dialyzer to remove metabolic waste products, excess fluid, and electrolytes from the circulation when native kidney function is inadequate. As an academic concept and research field, hemodialysis investigates its underlying physiological principles, technological advancements in dialyzer design and treatment delivery, clinical efficacy, patient outcomes, complications, and optimal management strategies, representing a critical life-sustaining intervention and a cornerstone area within nephrology and critical care.