If you have to go through dialysis this usually specifically means that you have a problem with your liver. Your liver is the thing in your body that cleans the toxins from your blood and helps to expel them from your body by secreting or excreting them. It cannot catch all of them but it catches a fair enough amount to keep you alive. This is why it is called a liver. Dialysis is the process of putting the blood through a machine that cleans it for you when your liver can't.
If you have a dream about dialysis it means that you feel as if you are dirty on the inside. You feel like you have done something wrong and you wish that you could wash yourself from the inside out. You want to clean your blood like a dialysis machine does. Not literally of course, but you feel dirty because of what you've done in the past and you wish you could undo some of it and achieve cleanliness for all of the hard work you're doing.
Dialysis dreams can also mean that you feel too dependent on others or on outside circumstances to help you with your problems. You are constantly looking to others to help you with your issues when you should be able to handle your own problems. This is not a good thing and you should not be worrying about how well you are or are not doing on living on your own. You can't always depend on others to help you get through your life, sometimes you just need to pull yourself up by your bootstraps and go out there and get the tough things in life done by yourself.