Which Mode to Choose: HD or HDF Mode?
Many people do not know the difference between HD and HDF; they only know about single-pump and double-pump systems. Let’s learn about their specific functions.
As is well known, dialysis is not just about removing water; more importantly, it is about removing toxins. Various modes of dialysis remove different large, medium and small molecular substances, thereby achieving the corresponding therapeutic effects.
The image above shows what people refer to as the single-pump system, which is the HD mode (Hemodialysis mode).
HD Hemodialysis Mode
Hemodialysis mode removes toxins through the process of diffusion.
Diffusion:
The movement of solutes through a semipermeable membrane from an area of high concentration to an area of low concentration. It primarily clears small molecular substances, such as sugars, electrolytes (Na, K, Ca, Cl), urea nitrogen, creatinine, and water.
The image above shows what people refer to as the double-pump system, which is the HDF mode (Hemodiafiltration mode).
HDF Hemodiafiltration Mode
Hemodiafiltration mode removes toxins through the process of convection.
Convection:
The relative displacement of fluids. The pressure difference across the semipermeable membrane is called transmembrane pressure, which is the driving force of convection. Under the action of transmembrane pressure, when liquid moves from the high-pressure side through the semipermeable membrane to the low-pressure side, it drags solutes along with it; this solute transport process is called convection. It primarily clears small and medium molecules. It can clean molecular substances cleared by the HD mode, as well as more medium molecular toxins (such as β2-microglobulin), more phosphorus, inflammation mediators (interleukin-6), and helps improve anemia, etc.
To summarize:
Of course the specific application should be implemented according to the doctor’s treatment plan.
It is recommended to HDF at least twice a month; if conditions permit, weekly HDF is possible.
We hope patients can understand the specific functions to achieve better treatment results.
Chengdu Wesley was established in 2006 and has been dedicated to the field of hemodialysis for 20 years, providing one-stop solutions to users worldwide. Please feel free to contact us!
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Post time: Apr-27-2026
