Dialysis helps damaged kidneys to remove wastes and extra fluid from the body. However, there are some chemicals that are not able to be taken out by the dialysis process. They are lots of chemicals in the body. We call them middle molecules and we do not have any standard way to measure them. So what we want to excrete are small particles. These middle molecules, some of them have hormonal effects. This is the reason why your skin gets darker and darker.
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