How a Dialysis Machine Works

A dialysis machine is often called an artificial kidney because it performs the blood-filtering function when the kidneys can no longer do so effectively.

Step-by-Step Process

Blood Withdrawal – A needle draws blood from the patient’s vein into the extracorporeal circuit.

Blood Pumping – A pump moves the blood at a controlled flow rate.

Dialyzer (Artificial Kidney) – The blood passes through a dialyzer, which contains a semipermeable membrane.

Toxins and excess water move across the membrane into the dialysate fluid.

Red blood cells and proteins stay in the bloodstream.

Dialysate Flow – Fresh dialysate solution flows in the opposite direction, carrying away waste.

Air and Pressure Monitoring – Sensors detect air bubbles, pressures, and flow consistency for safety.

Clean Blood Return – The filtered blood is returned to the patient’s circulation.

This continuous cycle lasts about 3–5 hours per session, several times per week.