Hemodialysis

Background

Hemodialysis (HD) is the process by which the solute composition of a solution (blood) is altered by exposing the solution to a second solution (dialysate) through a semipermeable membrane. Low-molecular-weight solutes easily interchange between the two solutions down a concentration gradient, but high-molecular-weight solutes will remain on either side of the membrane unchanged. Solutes pass through the membrane via two different mechanisms: diffusion and convection (ultrafiltration).