The differences between hemodialysis and hemofiltration are removing substances, working principle, effect and so on. 1. Removal of substances: the former mainly removes small molecule solutes such as creatinine in the blood, and also removes excessive fluid in the body: the latter is more effective in removing medium and large molecule solutes. 2. Working principle: the former utilizes the principle of dispersion, which is to move from the side of high concentration to the side of low concentration by using the concentration difference between the two sides; the latter is based on the principle of convection, which utilizes the pressure gradient to move from the high-pressure side to the low-pressure side. 3. Effect: The latter will be more effective in maintaining blood pressure stability and improving myocardial ischemia. In the treatment, the specific choice of which way, need to be decided by a professional doctor after assessing the condition.