In simple words , a dialyzer is an artificial kidney for humans. It’s a filter-like product filled with synthetic membrane which can remove waste products from blood . Below is the image of dialyzer.

The structure of the dialyzer is made of plastic tube of one to two inches diameter closed on both ends and field with semipermeable membranes . There are two holes on top and bottom of the dialyzer. During the process of hemodialysis the dialyzer comes to touch with blood and dialysate simultaneously. Dialysate is a specific composition of electrolyte and chemical which is used by the hemodialysis machine to pull waste products from blood. When this process is running the waste product from the blood enters to the dialysate via the tyne membrane holes. This membrane also prevents blood cell and protein molecules from entering to dialysate.
There are two types of Dialyzer.
1. High Flux Dialyzer
2. Low Flux Dialyzer
High Flux Dialyzer
A high flux dialyzer is a specialized type of dialyzer designed to facilitate more efficient removal of waste products and toxins during dialysis. Unlike conventional dialyzers, high flux dialyzers have larger membrane pore sizes, allowing for enhanced permeability. This increased permeability enables better clearance of substances, such as middle molecular weight solutes, which are typically more challenging to remove with conventional dialysis.
How Does a High Flux Dialyzer Work?
High flux dialyzers operate based on the principles of diffusion and convection. During the dialysis procedure, blood and dialysate flow on either side of a semipermeable membrane. As the blood passes through the dialyzer, waste products, toxins, and excess fluids diffuse across the membrane into the dialysate.
A high flux dialyzer is designed with a more permeable membrane compared to a low flux dialyzer. This increased permeability allows the removal of larger molecules, such as certain toxins and inflammatory substances, during the dialysis process. High flux dialyzers are particularly useful for patients with conditions that result in the accumulation of larger molecules in their bloodstream.
Example of High Flux Dialyzer:
Fresenius F60s is the best high flux dialyzer which has more ultrafiltration as compared to other available dialyzers. Its ultrafiltration coefficient is 40 (ml/h x mmHg). Other best high flux dialyzers are F40S, F50S, F70S, F80S, HDF100S

Low Flux Dialyzer:
Low Flux dialyzers are another types of dialyzers which are used in the process of dialysis. It is designed with a membrane that has smaller pore size as compared to high flux dialyzers. The smaller pore size restricts the movement of larger solutes and which limits the clearance of large molecules from blood during dialysis.
How Does a Low Flux Dialyzer Work?
In a low flux dialyzer the blood moves through the dialyzer in contact with dialysate. When blood passes through the dialyzer , the waste products and excess fluids diffuse across the membrane into the dialysate. But due to smaller pore sizes the large molecules from blood cannot enter into the dialysate. Commonly low flux dialyzers are used in most of the cases of kidney failure .
Example of Low flux dialyzer :
Fresenius F6HPS is the best example of low flux dialyzer which has an ultrafiltration coefficient is 13 (ml/h x mmHg). Also the other low flux dialyzers are F4HPS, F5HPS, F7HPS, F8HPS, F10Hps and all the Fx class dialyzer of Fresenius such as Fx5,Fx8 and Fx10 are the examples of Low Flux Dialyzer .
